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It has been suggested that cannabis consumption during adolescence may be an initial step to cocaine use in adulthood. Indeed, previous preclinical data show that adolescent exposure to cannabinoids (both natural and synthetic) potentiates cocaine self-administration in rats. Here we aimed at gaining a deeper understanding of the cellular activation patterns induced by cocaine as revealed by Fos imaging and how these patterns may change due to adolescent exposure to THC. Male and female Wistar rats were administered every other day THC (3 mg/kg i.p.) or vehicle from postnatal day 28-44. At adulthood (PND90) they were given an injection of cocaine (20 mg/kg i.p.) or saline and sacrificed 90 min later. Cocaine-induced Fos activation was measured by immunohistochemistry as an index of cellular activation. We found that cocaine-induced activation in the motor cortex was stronger in THC-exposed rats. Moreover, there was significant sex-dependent interaction between cocaine and adolescent THC exposure in the dorsal hypothalamus, suggesting that cocaine induced a more robust cellular activation in THC-exposed females but not in THC-treated males. Other THC- and cocaine-induced effects were also evident. These results add to the previous literature suggesting that the behavioral, cellular, molecular, and brain-activating actions of cocaine are modulated by early experience with cannabinoids and provide additional knowledge that may explain the enhanced actions of cocaine in rats exposed to cannabinoids during their adolescence., (Copyright © 2021 Elsevier B.V. All rights reserved.)

We investigated a triple transgene Alzheimer's disease (AD) mouse model that recapitulates many of the neurochemical, anatomic, pathologic and behavioral defects seen in human AD. We studied the mice as a function of age and brain region and investigated potential therapy with the non-steroidal anti-inflammatory drug ibuprofen. Magnetic resonance spectroscopy (MRS) showed alterations characteristic of AD (i.e. increased myo-inositol and decreased N-acetylaspartate (NAA)). Mice at 6 months of age showed an increase in myo-inositol in the hippocampus at a time when the Aβ is intracellular, but not in amygdala or cortex. Myo-inositol increased as a function of age in the amygdala, cortex and striatum while NAA decreased only in the hippocampus and cortex at 17-23 months of age. Ibuprofen protected the increase of myo-inositol at six months of age in the hippocampus, but had no effect at 17-23 months of age (a time when Aβ is extracellular). In vivo MRI and MRS showed that at 17-23 months of age there was a significant protective effect of ibuprofen on hippocampal volume and NAA loss. Together, these data show the following: the increase in myo-inositol occurs before the decrease in NAA in hippocampus but not cortex; the hippocampus shows earlier changes than does the amygdale or cortex consistent with earlier deposition of Aβ40-42 in the hippocampus and ibuprofen protects against multiple components of the AD pathology. These data also show a profound effect of housing on this particular mouse model., (Published by Elsevier B.V.)

C57BL/6J and 129 substrains of mice are known to differ in their basal levels of anxiety and behavioral response to drugs of abuse. We have previously shown strain differences in heroin-induced conditioned place preference (CPP) between C57BL/6J (C57) and 129P3/J (129) mice, and in the regional expression of several receptor and peptide mRNAs. In this study, we examined the contribution of the GABAergic system in the cortex, nucleus accumbens (NAc), caudate putamen (CPu) and the region containing the substantia nigra and ventral tegmental area (SN/VTA) to heroin reward by measuring mRNA levels of 7 of the most commonly expressed GABA-A receptor subunits, and both GABA-B receptor subunits, in these same mice following saline (control) or heroin administration in a CPP design. Using real-time PCR, we studied the effects of strain and heroin administration on GABA-A α1, α2, α3, β2, and γ2 subunits, which typically constitute synaptic GABA-A receptors, GABA-A α4 and δ subunits, which typically constitute extrasynaptic GABA-A receptors, and GABA-B R1 and R2 subunits. In saline-treated animals, we found an experiment-wise significant strain difference in GABA-Aα2 mRNA expression in the SN/VTA. Point-wise significant strain differences were also observed in GABA-Aα2, GABA-Aα3, and GABA-Aα4 mRNA expression in the NAc, as well as GABA-BR2 mRNA expression in the NAc and CPu, and GABA-BR1 mRNA expression in the cortex. For all differences, 129 mice had higher mRNA expression compared to C57 animals, with the exception of GABA-BR1 mRNA in the cortex where we observed lower levels in 129 mice. Therefore, it may be possible that known behavioral differences between these two strains are, in part, due to differences in their GABAergic systems. While we did not find heroin dose-related changes in mRNA expression levels in C57 mice, we did observe dose-related differences in 129 mice. These results may relate to our earlier behavioral finding that 129 mice are hyporesponsive to the rewarding effects of heroin., (Copyright © 2013. Published by Elsevier B.V.)

Several demyelinating syndromes have been linked to mutations in glial gap junction proteins, the connexins. Although mutations in connexins of the myelinating cells, Schwann cells and oligodendrocytes, were initially described, recent data have shown that astrocytes also play a major role in the demyelination process. Alterations in astrocytic proteins directly affect the oligodendrocytes' ability to maintain myelin structure, and associated astrocytic proteins that regulate water and ionic fluxes, including aquaporins, can also regulate myelin integrity. Here, we will review the main evidence from human disorders and transgenic mouse models that implicate glial gap junction proteins in demyelinating diseases and the therapeutic potential of some of these targets. This article is part of a Special Issue entitled Electrical Synapses., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Many women continue to consume low to moderate quantities of alcohol during pregnancy, which can result in the variable neurobehavioural effects in the absence of physiological abnormalities that characterize fetal alcohol spectrum disorders (FASD). Previously, we reported that a mouse model for FASD based on voluntary maternal ethanol consumption throughout gestation resulted in offspring that showed mild developmental delay, anxiety-related traits, and deficits in spatial learning. Here, we extend this model by evaluating the gene expression changes that occur in the adult brain of C57BL/6J mice prenatally exposed to ethanol via maternal preference drinking. The results of two independent expression array experiments indicate that ethanol induces subtle but consistent changes to global gene expression. Gene enrichment analysis showed over-represented gene ontology classifications of cellular, embryonic, and nervous system development. Molecular network analysis supported these classifications, with significant networks related to cellular and tissue development, free radical scavenging, and small molecule metabolism. Further, a number of genes identified have previously been implicated in FASD-relevant neurobehavioural phenotypes such as cognitive function (Ache, Bcl2, Cul4b, Dkc1, Ebp, Lcat, Nsdh1, Sstr3), anxiety (Bcl2), attention deficit hyperactivity disorder (Nsdh1), and mood disorders (Bcl2, Otx2, Sstr3). The results suggest a complex residual "footprint" of neurodevelopmental ethanol exposure that may provide a new perspective for identifying mechanisms that underlie the life-long persistence of FASD-related cognitive and behavioural alterations, including potential targets for treatment., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Previous evidence indicates that a balance between inhibitory gabaergic and excitatory angiotensinergic factors in the PVN is important for cardiovascular control. We investigated the cardiovascular response evoked from activation or blockade of GABA(A) receptors in the paraventricular nucleus (PVN), in transgenic rats with low brain angiotensinogen [TGR(ASrAOGEN)]. Brain Ang II and Ang-(1-7) levels were also determined. In functional experiments, TGR(ASrAOGEN) and Sprague-Dawley rats (SD, control) were anesthetized with urethane and blood pressure (BP), heart rate (HR) and renal sympathetic nerve activity (RSNA) were recorded. Brain Ang II and Ang-(1-7) levels were largely reduced in TGR(ASrAOGEN) compared with SD rats. Inhibition of PVN neurons with the GABA(A) agonist, muscimol (1 nmol/100 nL), resulted in an attenuated fall in all cardiovascular variables in TGR(ASrAOGEN) compared with SD rats. This difference was particularly pronounced in HR (TGR Mus -23±6 bpm vs. -77±9 bpm SD Mus; P<0.05) and RSNA (TGR -3±10% vs.-29±8% SD; P<0.05). Furthermore, the sympathetic response evoked by blockade of GABA(A) receptors in the PVN of TGR(ASrAOGEN) was also largely suppressed. The present data indicate that the sympathetic outflow mediated by PVN neurons under basal conditions is suppressed in TGR(ASrAOGEN) rats corroborating the functional significance of brain angiotensin production in the central regulation of sympathetic output to the cardiovascular system., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Presenilin-1 (PS1) is a multifunctional protein involved in many cellular functions including the processing of type 1 membrane proteins such as β-amyloid precursor protein (APP) and Notch 1 receptor. PS1 acts as the catalytic subunit of the γ-secretase complex, and participates in Notch 1 processing to release Notch intracellular domain (NICD) in the cytoplasm. NICD subsequently migrates to the nucleus and causes Notch signaling by increasing the expression of the Hes1 gene. We have previously shown that inhibition of basal activity of c-jun-NH2-terminal kinase (JNK) with JNK-specific inhibitor SP600125 represses the expression of PS1 and γ-secretase activity by increasing p53 level in SK-N-SH cell line in vitro (Lee and Das, 2008, 2010). However, it is largely unknown whether PS1 can be effectively suppressed in vivo in adult mouse brains. In this report we showed that intraperitoneal (i.p) injection of JNK-specific inhibitor SP600125 decreased p-JNK level, and reduced PS1 expression by increasing p53 level in adult mouse brains. We also showed that suppression of PS1 expression by SP600125 reduced γ-secretase activity which decreased Notch 1 processing to reduce NICD in mouse brains. Furthermore, inhibition of Notch 1 processing by SP600125 decreased Notch 1 signaling by reducing the expression of the NICD target Hes1 gene in mouse brains without induction of apoptosis. These results provide insights for further study on PS1-mediated reduction of Notch 1 and APP processing for the treatment of Alzheimer's disease., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Neurotensin (NT) is a 13 amino acid neuropeptide that is identical in mice and humans and is released from and acts upon a number of social brain regions. Recent work indicates NT neurotransmission may be altered in postpartum females and support the onset of some maternal behaviors. In a recent study, we highlighted how virgin and postpartum brains from mice selected for high offspring protection differ in response to injected NT (0.1 μg) relative to vehicle when examining c-Fos profiles across the CNS. In this companion study we use a second marker for brain activity, Egr-1, and evaluate multiple brain regions. Common significant increased Egr-1 responses to NT (relative to vehicle) were found in both female groups only in ventromedial hypothalamus. In lateral periaqueductal gray, virgin mice showed a significant Egr-1 increase with NT (relative to vehicle), but maternal mice did not. When comparing NT injections, virgin (relative to maternal) mice had significantly higher activity in five regions, including anterior hypothalamus, lateral hypothalamus, somatosensory cortex, paraventricular nucleus, and zona incerta; no regions were higher in maternal mice. A Principal Components Analysis was also used for data mining and in virgin mice, greater changes in activity hubs were found with NT (relative to vehicle) than for maternal mice. Overall, a lower sensitivity to NT in terms of Egr-1 reactivity in the maternal state was highlighted and this is consistent with previous c-Fos results. These findings provide additional insight into the mechanisms by which NT functions in the CNS., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Neuropeptide Y (NPY) and its receptors are present in the peripheral as well as the central nervous system (CNS). In vitro data have indicated NPY as an important mediator in the regulation of different diseases e.g. related to obesity, anxiety, depression, pain, memory loss and sleep disorders. In particular, studies of NPY levels in the cerebral spinal fluid (CSF) of depressed patients have shown a significant reduction of NPY levels when compared to control subjects. In addition, decreased concentrations of NPY were measured in the brain of suicide victims. These studies suggest that a reduction in cerebral NPY function may be associated with depressive symptoms. In the present work, a putative interaction between NPY, the catecholaminergic and serotonergic systems has been analysed by means of in vivo Differential Pulse Voltammetry (DPV) with treated carbon fibre micro electrodes (mCFE). It appeared that DPV with mCFE is an efficacious tool to monitor in vivo basal levels of catechols (Peak 2) and indoles (Peak 3) in discrete brain regions of rodents. Furthermore, it is shown that the peptidergic signal (Peak 5) simultaneously recorded with Peaks 2 and 3 in the amygdala could correspond to the oxidation of basal endogenous NPY. In addition, pharmacological treatments performed in vivo with exogenous NPY and with Y1 receptor antagonist BIBP3226 have indicated that these compounds interact positively with endogenous catecholaminergic and serotoninergic systems, in a way similar to that of the antidepressants imipramine and fluoxetine. In addition, the observed decrease of endogenous Peak 5 after treatment with imipramine or fluoxetine could be related to the concomitant stimulation of the catecholaminergic system with consequent reduced need for endogenous NPY. This would imply that NPY could be one of the endogenous chemicals acting on the maintenance of the mood. Thus, an antidepressant therapeutic potential of NPY and related compounds (e.g. BIBP3226) could be proposed., (Copyright © 2011. Published by Elsevier B.V.)

Some individuals control their ethanol consumption throughout life, but others escalate their intake to levels that increase the risk for addiction. The early environment influences the individual response to ethanol and affects the underlying physiological processes that lead to a transition from a voluntary to a compulsive use of ethanol. However, the neurobiological substrates for these processes are not understood. The present study aimed to test the hypothesis that early environmental experiences affect the neurobiological effects that are induced by voluntary ethanol consumption. Rat pups were subjected to three different rearing environments: conventional animal facility rearing or separation from dam and littermates for either 15 or 360min. In adulthood, the rats were exposed to a two-bottle free choice between ethanol and water for seven weeks. Tissue levels of dopamine, 5-hydroxytryptamine (5-HT) and their metabolites were measured in brain areas that have been implicated in reward and addiction processes. Differences in ethanol-induced effects were noted in 5-HT-related measurements in the nucleus accumbens and ventral tegmental area and in dopamine-related measurements in the dorsal raphe nucleus (DRN). These results provided evidence of an early environmental impact on interactive neuronal circuits between the DRN and reward pathways. The amygdala, a key area in addiction processes, was particularly sensitive to early-life conditions. The animals that experienced the longest separation differed from the others; they had low basal 5-HT levels and responded with an increase in 5-HT after ethanol. These altered responses to initial ethanol consumption as a result of early environmental factors may affect the transition from habitual to compulsive drinking and contribute to individual vulnerability or resilience to addiction., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Lactate has been identified as an alternative fuel for the brain in situations of increased energy demand, as following a traumatic brain injury (TBI). This study investigates the effect of treatment with sodium lactate (NaLac) on the changes in brain energy state induced by a severe diffuse TBI. Rats were assigned to one of the eight groups (n=10 per group): 1-sham, normal saline; 2-TBI, normal saline; 3-TBI, hypertonic saline; 4-TBI, 100mM NaLac, 5-TBI, 500 mM NaLac; 6-TBI, 1280 mM NaLac; 7-TBI, 2000 mM NaLac and 8-TBI-500 mM NaLac+magnesium sulfate. Cerebrums were removed 6h after trauma. Metabolites representative of the energy state (ATP, ATP-catabolites), N-acetylaspartate (NAA), antioxidant defenses (ascorbic acid, glutathione), markers of oxidative stress (malondialdehyde, ADP-ribose) and nicotinic coenzymes (NAD(+)) were measured by HPLC. TBI induced a marked decrease in the cerebral levels of ATP, NAA, ascorbic acid, glutathione and NAD(+) and a significant rise in the content of ATP-catabolites, malondialdehyde and ADP-ribose. These alterations were not ameliorated with NaLac infusion. We observed a significant reduction in cerebral NAD(+), an essential co-enzyme for mitochondrial lactate-dehydrogenase that converts lactate into pyruvate and thus replenishes the tricarboxylic acid cycle. These results suggest that the metabolic pathway necessary to consume lactate may be compromised following a severe diffuse TBI in rats., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Pristanic acid (Prist) is accumulated in various peroxisomal disorders characterized by severe neurological dysfunction whose pathogenesis is poorly understood. Since oxidative damage has been demonstrated in brain of patients affected by neurodegenerative disorders, in the present work we investigated the in vitro effects of Prist on important parameters of oxidative stress in cerebral cortex from young rats. Prist significantly increased malondialdehyde levels, reflecting an increase of lipid peroxidation. This effect was totally prevented by the free radical scavenger melatonin, suggesting the involvement of reactive species. Prist also provoked protein oxidative damage, as determined by increased carbonyl formation and sulfhydryl oxidation. Otherwise, it did not alter nitric oxide production, indicating that nitrogen reactive species were not implicated in the lipid and oxidative damage provoked by Prist. Furthermore, the concentration of glutathione (GSH), the major brain non-enzymatic antioxidant defense, was significantly decreased by Prist and this decrease was fully prevented by melatonin and attenuated by α-tocopherol. It is therefore presumed that Prist elicits oxidative stress in the brain probably via reactive oxygen species formation and that this pathomechanism may possibly be involved in the brain damage found in patients affected by peroxisomal disorders where Prist accumulates., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Cyclosporine A (CsA) is neuroprotective in ischemic brain injuries of adult animals because it blocks the permeability transition of the mitochondrial membrane. In this study, we examined the neuroprotective effect of CsA on hypoxia-ischemia (HI)-induced brain injury in newborn rats. Seven-day-old Sprague-Dawley rat pups were subjected to 2h of 8% oxygen following a unilateral carotid artery ligation. With a single dose of CsA treatment (20mg/kg, intraperitoneal) given immediately after HI, the HI-induced decrease in brain mitochondrial membrane potential measured with 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) and adenosine triphosphate levels, and increase in the brain lactate level, both apoptotic and necrotic cells measured with annexin V and propidium iodide (V-PI), and infarct area measured with 2,3,5-triphenyltetrazolium chloride (TTC) were significantly attenuated at 48 h, and the reduced brain volume also significantly improved 2 weeks following HI. In summary, Cyclosporine A, a mitochondrial permeability transition blocker, significantly attenuated hypoxia-ischemia-induced lowering of the mitochondrial membrane potential, cerebral energy status, increased apoptotic and necrotic cells, and the ensuing cerebral infarction in the immature brain., (Copyright © 2010 Elsevier B.V. All rights reserved.)

The forced swim test (FST) is a behavioral paradigm that is predicative of antidepressant activity in rodents. The objective of this study was to examine the effects of desipramine (DMI) pretreatment on behavioral and regional neurochemical responses in the left dorsolateral prefrontal cortex (DLPFC) and hippocampus of mice exposed to the FST using proton magnetic resonance spectroscopy ((1)H-MRS). An ultra short echo stimulated echo acquisition (STEAM) localization sequence (TR/TM/TE=5000/20/2.2ms) was used to measure in vivo proton spectra from the left DLPFC (voxel volume: 7microl) and hippocampus (6microl) of C57BL/6 mice at 9.4T and acquired proton spectra post-processed offline with LCModel. The FST induced significant increase of glutamate (Glu) and myo-inositol (mIns) concentrations in the left DLPFC and hippocampus, respectively. In addition, creatine+phosphocreatine (Cr+PCr) concentrations in the left DLPFC were significantly decreased as compared to control. The metabolic alterations induced by the FST were reverted to level similar to control by acute DMI administration. Our results suggest that glutamatergic activity and glial cell dysfunction may contribute to the pathophysiological mechanisms underlying depression and that modulation of synaptic neurotransmitter concentrations represents a potential target for antidepressant drug development., (Copyright 2010 Elsevier B.V. All rights reserved.)

The goal of this study was twofold: (a) to search for possible interactive effects between two common drugs of abuse, ethanol and methamphetamine. b) To inquire whether any effects of ethanol could be replicated using an equivalent amount of ethanol in the form of red wine. Adult male C57/6N mice received 2% ethanol for 8 weeks in drinking water or red wine diluted to yield the same ethanol content. On the 9th week animals received multiple injections of methamphetamine (4 x 10 mg/kg, ip, every 2 h). They were then sacrificed 72 h after treatment. Methamphetamine produced a significant depletion of dopamine and DOPAC in the striatum. Treatment with both ethanol and methamphetamine led to a reduction of striatal dopamine and DOPAC that were both non-significantly greater than that observed with methamphetamine alone. Alcohol alone produced no changes in the striatal content of dopamine or its metabolite, DOPAC. These data suggest that low doses of alcohol potentiate methamphetamine-induced neurotoxicity in mice and that this combination may be especially detrimental to the brain. However, an equivalent dose of ethanol in the form of red wine actually partially protected against methamphetamine-induced depletion of dopamine and DOPAC in red wine treated mice. This implies the presence of other agents in red wine, which may mitigate the toxicity of methamphetamine., (Copyright 2010 Elsevier B.V. All rights reserved.)

Studies of rodent grooming can provide valuable insight for dopamine contributions to the initiation, organization, and repetition of motor patterns. This information is useful for understanding how brain dysfunctions contribute to movement disorders such as Tourette syndrome and obsessive compulsive disorder, in which patients are driven to reiterate particular movement patterns. In rodents, dopamine D1 receptor stimulation causes a complex behavioral super-stereotypy in the form of excessive production and rigid execution of whole sequences of movements known as syntactic grooming chains. Sequential super-stereotypy of grooming chains may be particularly advantageous for modeling movement sequences and treatments in Tourette syndrome and related disorders. Here, we report that co-administration of haloperidol, one available treatment for Tourette syndrome and primarily a D2 receptor antagonist, prevented D1 stimulation with SKF38393 from inducing sequential super-stereotypy, which manifests as an exaggeration of the tendency to complete all four phases of a syntactic chain in rigid serial order once the first phase has begun. In a separate experiment, we showed that in contrast to acute D1 agonist administration, 39h withdrawal from chronic (3weeks) administration of the D1 antagonist SCH23390 (which has been suggested to increase D1 receptor expression in the basal ganglia) did not elicit sequential super-stereotypy after drug cessation. Instead, rats suddenly removed from repeated SCH23390 spent more time performing simple stereotypies that included intense scratching and biting behaviors. Together, these results have implications for understanding how dopamine receptors facilitate particular stereotypies manifest in animal models of Tourette syndrome and obsessive compulsive disorder., (Copyright 2010 Elsevier B.V. All rights reserved.)

Drug addiction is one of the top three health concerns in the United States in terms of economic and health care costs. Despite this, there are very few effective treatment options available. Therefore, understanding the causes and molecular mechanisms underlying the transition from casual drug use to compulsive drug addiction could aid in the development of treatment options. Studies in humans and animal models indicate that stress can lead to both vulnerability to develop addiction, and increased drug taking and relapse in addicted individuals. Exposure to stress or drugs of abuse results in long-term adaptations in the brain that are likely to involve persistent alterations in gene expression or activation of transcription factors, such as the cAMP Response Element Binding (CREB) protein. The signaling pathways controlled by CREB have been strongly implicated in drug addiction and stress. Many potential CREB target genes have been identified based on the presence of a CRE element in promoter DNA sequences. These include, but are not limited to CRF, BDNF, and dynorphin. These genes have been associated with initiation or reinstatement of drug reward and are altered in one direction or the other following stress. While many reviews have examined the interactions between stress and addiction, the goal of this review was to focus on specific molecules that play key roles in both stress and addiction and are therefore posed to mediate the interaction between the two. Focus on these molecules could provide us with new targets for pharmacological treatments for addiction., (Copyright 2009 Elsevier B.V. All rights reserved.)

From the earliest work in our laboratory, we hypothesized, and with studies conducted in both clinical research and animal models, we have shown that drugs of abuse, administered or self-administered, on a chronic basis, profoundly alter stress-responsive systems. Alterations of expression of specific genes involved in stress responsivity, with increases or decreases in mRNA levels, receptor, and neuropeptide levels, and resultant changes in hormone levels, have been documented to occur after chronic intermittent exposure to heroin, morphine, other opiates, cocaine, other stimulants, and alcohol in animal models and in human molecular genetics. The best studied of the stress-responsive systems in humans and mammalian species in general is undoubtedly the HPA axis. In addition, there are stress-responsive systems in other parts in the brain itself, and some of these include components of the HPA axis, such as CRF and CRF receptors, along with POMC gene and gene products. Several other stress-responsive systems are known to influence the HPA axis, such as the vasopressin-vasopressin receptor system. Orexin-hypocretin, acting at its receptors, may effect changes which suggest that it should be properly categorized as a stress-responsive system. However, less is known about the interactions and connectivity of some of these different neuropeptide and receptor systems, and in particular, about the possible connectivity of fast-acting (e.g., glutamate and GABA) and slow-acting (including dopamine, serotonin, and norepinephrine) neurotransmitters with each of these stress-responsive components and the resultant impact, especially in the setting of chronic exposure to drugs of abuse. Several of these stress-responsive systems and components, primarily based on our laboratory-based and human molecular genetics research of addictive diseases, will be briefly discussed in this review., (Copyright 2009 Elsevier B.V. All rights reserved.)

We investigated the neurochemical mechanism of how high-dose ethanol exposure may increase motivation for ethanol consumption. First, we developed an animal model of increased motivation for ethanol using a progressive ratio (PR) schedule. Sprague-Dawley rats were trained to administer 10% ethanol-containing gelatin or plain gelatin (on alternate weeks) in daily 30-min sessions under different fixed ratio (FR) and PR schedules. During FR schedules, rats self-administered about 1 g/kg ethanol, which was decreased to 0.4+/-0.03 g/kg under PR10. Rats then received four pairs of either 3 g/kg ethanol or saline injections during the weeks when the reinforcer was plain gelatin. During subsequent ethanol gel sessions, breakpoints and ethanol consumption rose 40% in the high-dose ethanol group by the fourth set of injections with no change in plain gel responding. Alterations in amino acids in the ventral striatum (VS) during PR10 responding for 10% ethanol gelatin and plain gelatin were measured using microdialysis sampling coupled with capillary electrophoresis and laser-induced fluorescence detection. There was greater release of taurine, glycine and glutamate in the NAC of the high-dose ethanol rats during 10% ethanol-containing gelatin responding, compared to the control rats or during plain gel responding. An increase in the release of glycine in this same brain region has recently been shown to be involved with anticipation of a reward. Thus, it appears that intermittent high-dose ethanol exposure not only increases motivation for ethanol responding but may also change neurotransmitter release that mediates anticipation of reinforcement, which may play a key role in the development of alcoholism., (Copyright 2009 Elsevier B.V. All rights reserved.)

Background: Intracerebral hemorrhage (ICH) is associated with neurological injury that may be ameliorated by a neuroprotective strategy targeting the complement cascade. We investigated the role of C5a-receptor antagonist (C5aRA) solely and in combination with C3a-receptor antagonist (C3aRA) following ICH in mice., Methods: Adult male C57BL/6J mice were randomized to receive vehicle, C5aRA alone or C3aRA and C5aRA 6 and 12 h after ICH, and every 12 h thereafter. A double injection technique was used to infuse 30 microL of autologous whole blood into the right striatum. A final group of mice received a sham procedure consisting only of needle insertion followed by vehicle injections. Brain water content and flow cytometry analysis for leukocyte and microglia infiltration and activation in both hemispheres were measured on day 3 post ICH. Neurological dysfunction was assessed using a Morris water-maze (MWM), a 28-point scale, and a corner test at 6, 12, 24, 48 and 72 h after ICH induction., Results: Neurological deficits were present and comparable in all three cohorts 6 h after ICH. Animals treated with C5aRA and animals treated with combined C3aRA/C5aRA demonstrated significant improvements in neurological function assessed by both the corner turn test and a 28-point neurological scale at 24, 48 and 72 h relative to vehicle-treated animals. Similarly, C5aRA and C3aRA/C5aRA-treated mice demonstrated better spatial memory retention in the Morris water-maze test compared with vehicle-treated animals (C3aRA/C5aRA: 23.4+/-2.0 s p< or =0.0001 versus vehicle: 10.0+/-1.7 s). Relative to vehicle-treated mice, the brain water content in C3aRA/C5aRA-treated mice was significantly decreased in the ipsilateral cortex and ipsilateral striatum (ipsilateral cortex: C3aRA/C5aRA: 0.755403+/-0.008 versus 0.773327+/-0.003 p=0.01 striatum: 0.752273+/-0.007 versus 0.771163+/-0.0036 p=0.02). C5aRA-treated mice and C3aRA/C5aRA-treated mice had a decreased ratio of granulocytes (CD45(+)/CD11b(+)/Ly-6G(+)) in the hemorrhagic versus non-hemorrhagic hemispheres relative to vehicle-treated animals (C5aRA: 1.78+/-0.36 p=0.02 C3aRA/C5aRA: 1.59+/-0.22 p=0.005 versus vehicle: 3.01)., Conclusions: While administration of C5aRA alone provided neuroprotection, combined C3aRA/C5aRA therapy led to synergistic improvements in neurofunctional outcome while reducing inflammatory cell infiltration and brain edema. The results of this study indicate that simultaneous blockade of the C3a and C5a receptors represents a promising neuroprotective strategy in hemorrhagic stroke.

Astroglial cells clear extracellular glutamate through the glutamate transporters, GLT-1 and GLAST, and subsequently convert the incorporated glutamate into glutamine by the enzyme, glutamine synthetase (GS). Several forms of acute brain injury are associated with the increased expression of GS and the decreased expression of GLT-1 and/or GLAST, eventually leading to the accumulation of excitotoxic extracellular glutamate concentrations. Although of clinical interest, the actual trigger of these injury-related changes of glial glutamate turnover remains unknown. Our present studies provide evidence that increases in extracellular glutamate, as present in many brain injuries, are sufficient to modulate the expression of glutamate transporters and GS. Subjecting cultured cortical astrocytes to glutamate concentrations of 0.5-20 mM resulted in a 25% loss of GLT-1 and GLAST protein levels after 24 h; GLT-1 and GLAST levels maximally decreased by 40% and 75%, respectively, after 72 h. This decline was not due to astroglial cell death, since glutamate up to 50 mM did not affect the survival of cultured astrocytes within 72 h. Major astrocytic cell death, however, occurred in cultures maintained under severe (4% O(2)), but not mild (9% O(2)), hypoxia, as well as in the presence of aspartate (>or=20 mM). Glutamate at >or=1 mM induced a prolonged increase of GS expression in contrast to glutamate transporters. Neither the decline of glutamate transporter expression nor the increase in GS expression induced by high extracellular glutamate was further modulated by mild hypoxia. Whereas the stimulatory influences of glutamate on GS expression were prevented by the non-competitive NMDA receptor antagonist, MK801, the inhibitory influences on glutamate transporter expression were neither sensitive to MK801, the non-competitive mGluR5 antagonist, MTEP, nor the non-competitive AMPA receptor antagonist, GYKI52466, implying that glutamate controls glial glutamate transport by a glutamate receptor-independent mechanism.

Lipoic acid (LA), an essential cofactor for mitochondrial enzymes and a natural antioxidant, has been explored for the treatment of Alzheimer's disease. However, lipoic acid distribution in brain has not been investigated via oral dosing in human subjects or animals. Therefore, we aim to investigate the distribution of orally administered LA from systemic circulation into rat brain tissues and understand the transport efficiency of lipoic acid across the blood-brain barrier. Brain and blood samples were obtained from male Lister Hooded rats at pre-defined time points after single and chronic oral dosing of LA at 50 mg/kg. Levels of LA were determined using liquid chromatography tandem mass spectrometry. An equilibrium dialysis method was employed to elucidate LA protein binding in brain and blood tissues. Basal endogenous levels of LA in control rats were found to fluctuate between 0.005 and 0.267 microM in blood and 0-0.024 microM in brain after correction for residual blood volume. Pharmacokinetic profiling demonstrated rapid biphasic elimination of LA in blood and poor distribution into various brain regions with levels ranging from 0.0009 to 0.0072 microM. The in vitro and in vivo LA brain:blood partition ratios were 0.1 and -0.01, respectively. Our results demonstrate for the first time that LA does not cross the blood-brain barrier readily and suggest that the antioxidant effect of LA in brain may not be due to its direct effect in the central nervous system.

The purpose of this review is to provide strategies and their rationale which can facilitate scientifically productive investigations into genetic, neuronal, brain functional and clinical aspects of bipolar disorder. The presentation addresses both factors that have impeded and those that have facilitated landmark advances on the pathophysiology and treatment of bipolar disorders. Application of the strategies can provide a scientific platform that may be useful to basic and clinical scientists for the purposes of achieving seminal advances in understanding pathophysiology, including inherited and experience based contributors to disease expression. Current diagnostic criteria omit certain key symptoms, do not include illness course or family history and lack specification of the importance of fundamental symptomatology. Consideration of such factors in inclusion and exclusion criteria, and in assessment instruments in basic and clinical studies, serves to strengthen the capability of a research plan to test key hypotheses regarding moderating and mediating factors of this complex illness. For example, most studies of brain structure and function and of new interventions have selected subjects on the basis of traditional full syndromal criteria. Evidence indicates that additional consideration of principal behavioral domains of bipolar symptomatology, e.g., anxiety, psychosis, impulsivity, elevated psychomotor and cognitive processing speed, rather than strictly depressive or manic syndromes can provide more homogeneous samples for study, and increase the focus of experimental hypotheses.

(S)-(2)-5-ethynyl-3-(1-methyl-2-pyrrolidinyl)pyridine HCl (SIB-1508Y, Altinicline), is a subtype-selective neuronal nicotinic acetylcholine receptor (nAChR) agonist. In rodents, SIB-1508Y exhibited antidepressant activity, reversed age-related decrements in vigilance, and improved motor and cognitive function in primate models of Parkinson's disease. The goal of the study was to explore neurochemical effects of SIB-1508Y and its isomer, SIB-1680WD. In vitro, SIB-1508Y increased dopamine (DA) release from slices of rat striatum, nucleus accumbens (NAc), olfactory tubercles (OT) and prefrontal cortices (PFC) in a concentration-dependent manner. Relative to its robust effects on DA release from various brain regions, SIB-1508Y was minimally effective at increasing NE release from hippocampus or PFC, and 5-HT release from PFC. SIB-1680WD was less potent and efficacious than SIB-1508Y, but did not act as a partial agonist. Subcutaneous injection of SIB-1508Y (10 mg/kg) increased striatal DA release and this release was sensitive to blockade by the non-competitive nAChR antagonist, mecamylamine (Mec). SIB-1508Y also increased hippocampal ACh release selectively without affecting striatal ACh release. Hippocampal ACh release evoked by SIB-1508Y was attenuated by nAChR antagonists Mec and Dihydro-beta-erythroidine (DHbetaE), and also by the DA D1 receptor antagonist, SCH-23390. These results are consistent with previously established pharmacology of nAChR regulation of hippocampal ACh release. Repeated administration of SIB-1508Y did not result in an enhanced striatal DA release or hippocampal ACh release. In summary, the abilities of SIB-1508Y to release multiple neurotransmitters in distinct brain regions may contribute to its behavioral profile.

It is well known that adenine-based purines exert multiple effects on pain transmission. However, less attention has been given to the potential effects of guanine-based purines (GBPs) on pain transmission. The aim of this study was to investigate the effects of intracerebroventricular (i.c.v.) guanosine and GMP on mice pain models. Mice received an i.c.v. injection of vehicle (saline or 10 muM NaOH), guanosine (5 to 400 nmol), or GMP (240 to 960 nmol). Additional groups were also pre-treated with i.c.v. injection of the A(1)/A(2A) antagonist caffeine (15 nmol), the non-selective opioid antagonist naloxone (12.5 nmol), or the 5'-nucleotidase inhibitor AOPCP (1 nmol). Measurements of CSF purine levels and cortical glutamate uptake were performed after treatments. Guanosine and GMP produced dose-dependent antinociceptive effects. Neither caffeine nor naloxone affected guanosine antinociception. Pre-treatment with AOPCP completely prevented GMP antinociception, indicating that conversion of GMP to guanosine is required for its antinociceptive effects. Intracerebroventricular administration of guanosine and GMP induced, respectively, a 180- and 1800-fold increase on CSF guanosine levels. Guanosine was able to prevent the decrease on cortical glutamate uptake induced by intraplantar capsaicin. This study provides new evidence on the mechanism of action of GBPs, with guanosine and GMP presenting antinociceptive effects in mice. This effect seems to be independent of adenosine and opioid receptors; it is, however, at least partially associated with modulation of the glutamatergic system by guanosine.

We reported a perspective animal model of neurodevelopmental disorders using rats prenatally exposed to an inhibitor of serotonin (5HT) synthesis, para-chlorophenylalanine (PCPA). Earlier, we demonstrated that prenatal exposure to PCPA caused fetal 5HT depletion and changes both in open field activity and in depression-related behavior, as well as impairments in spatial learning in the adult offspring (Vataeva et al., 2007). The present study revealed that prenatal PCPA treatment resulted in the offspring's significantly reduced anxiety-related behavior in the elevated plus-maze and reduced neophobia to intake fluids in a novel environment. These effects are accompanied by hedonic changes in the form of an appropriate increase in saccharin preference. We confirmed our earlier finding that prenatal PCPA exposure affected the open field locomotor activity. In the present study we have shown that the selective 5HT reuptake inhibitor (SSRI) paroxetine decreases locomotor activity in the prenatally PCPA-treated offspring. It was also found that in the PCPA-treated fetal brain, 5HT depletion was associated with a significant decrease in the level of dopamine (DA) metabolite dihydroxyphenylacetic acid (DOPAC) and with a reduction of DOPAC/DA and homovanillic acid (HVA)/DA ratios. An assay of adult offspring brain revealed that the prenatal PCPA produced different effects on monoamines in the studied brain structures. The relationships between behavioral abnormalities and alterations in brain monoamine levels consequent on the prenatal PCPA treatment are discussed.

The present study was designed with an aim to evaluate the effects of chronic aluminium exposure (10 mg/kg b.wt, intragastrically for 12 weeks) on mitochondrial energy metabolism in different regions of rat brain in vivo. Mitochondrial preparations from aluminium treated rats revealed significant decrease in the activity of various electron transport complexes viz. cytochrome oxidase, NADH cytochrome c reductase and succinic dehydrogenase as well, in the hippocampus region. The decrease in the activity of these respiratory complexes was also seen in the other two regions viz. corpus striatum and cerebral cortex, but to a lesser extent. This decrease in the activities of electron transport complexes in turn affected the ATP synthesis and ATP levels adversely in the mitochondria isolated from aluminium treated rat brain regions. We also studied the spectral properties of the mitochondrial cytochromes viz. cyt a, cyt b, cyt c1, and cyt c in both control and treated rat brains. The various cytochrome levels were found to be decreased following 12 weeks of aluminium exposure. Further, these impairments in mitochondrial functions may also be responsible for the production of reactive oxygen species and impaired antioxidant defense system as observed in our study. The electron micrographs of neuronal cells depicted morphological changes in mitochondria as well as nucleus only from hippocampus and corpus striatum regions following 12 weeks exposure to aluminium. The present study thus highlights the significance of altered mitochondrial energy metabolism and increased ROS production as a result of chronic aluminium exposure in different regions of the rat brain.

The possible long-term effects of the recreational drug "ecstasy" (3,4-methylenedioxymethamphetamine, MDMA) on the function of 5-hydroxytryptamine-1B (5-HT(1B)) receptor in sleep and motor control were investigated using a selective 5-HT(1B) receptor agonist, 5-propoxy-3-(1,2,3,6-tetrahydro-4-pyrinzidyl)-1H-pyrrolo([3,2-b])pyridine hydrochloride (CP-94,253; 5 mg/kg). CP-94,253 or vehicle was administered to freely moving rats pre-treated with MDMA (15 mg/kg) or vehicle 6 months earlier, and polygraphic recording for 24 h and motor activity measurements were performed. Active wake (AW), passive wake (PW), light slow wave sleep (SWS-1), deep slow wave sleep (SWS-2), paradoxical sleep (PS), and diurnal rhythm were analyzed for the whole period. In additional, the EEG power spectrum was calculated for the second hour after the acute treatment for AW, PW, SWS-1, and SWS-2. 5-HT transporter (5-HTT) immunohistochemistry was measured in brain areas related to sleep and motor control 6 months after MDMA treatment. CP-94,253 increased AW and PW, decreased SWS-2 and PS, and altered parameters of diurnal rhythm in control animals. CP-94,253 decreased the EEG power spectra at higher frequencies. The effects of CP-94,253 on AW and diurnal rhythm were reduced or eliminated in MDMA-treated animals. MDMA treatment decreased 5-HTT fibre density in posterior hypothalamus, tuberomammillary nucleus, caudate putamen and ventrolateral striatum. These data suggest that long-term changes in 5-HT(1B) receptor function occur after serotonergic damage caused by a single dose of MDMA.

NT69L, is a novel neurotensin (8-13) analog that participates in the modulation of the dopaminergic pathways implicated in addiction to psychostimulants. NT69L blocks nicotine-induced hyperactivity as well as the initiation and expression of sensitization in rats. Recent evidence suggests that stimulation of mesocorticolimbic dopamine system, with influences from the other monoamine systems, e.g. norepinephrine and serotonin, is involved in nicotine's reinforcing properties. The aim of the present study was to investigate the effect of pretreatment with NT69L on nicotine-induced changes in monoamine levels in the rat brain using in vivo microdialysis. Acute or chronic (0.4 mg/kg, sc, once daily for 2 weeks) administration of nicotine elicited increases in extracellular levels of dopamine, dopamine metabolites, norepinephrine, or serotonin in medial prefrontal cortex, nucleus accumbens shell, and core of rats. Pretreatment with NT69L (1 mg/kg, intraperitoneally, ip) administered 40 min before nicotine injection significantly attenuated the acute nicotine-evoked increases in norepinephrine levels in medial prefrontal cortex, dopamine and serotonin in nucleus accumbens shell. After chronic nicotine administration, pretreatment of NT69L markedly reversed the increase in dopamine levels in the nucleus accumbens core. NT69L's attenuation of some of the biochemical effects of acute and chronic nicotine is consistent with this peptide's attenuation of nicotine-induced behavioral effects. These data further support a role for NT69L or other neurotensin receptor agonists to treat nicotine addiction.

Shiga toxin (Stx) from enterohemorrhagic Escherichia coli (STEC) is the main cause of hemorrhagic colitis which may derive into Hemolytic Uremic Syndrome (HUS) and acute encephalopathy, one of the major risk factors for infant death caused by the toxin. We have previously demonstrated that intracerebroventricular administration of Stx2 causes neuronal death and glial cell damage in rat brains. In the present work, we observed that the intracerebroventricular administration of Stx2 increased the expression of glial fibrillary acidic protein (GFAP) leading to astrogliosis. Confocal microscopy showed reactive astrocytes in contact with Stx2-containing neurons. Immunocolocalization of increased GFAP and Stx2 in astrocytes was also observed. This insult in the brain was correlated with changes in the expression and activity of neuronal nitric oxide synthase (nNOS) by using the NADPH-diaphorase histochemical technique (NADPH-d HT). A significant decrease in NOS/NADPH-d-positive neurons and NOS/NADPH-d activity was observed in cerebral cortex and striatum, whereas an opposite effect was found in the hypothalamic paraventricular nucleus. We concluded that the i.c.v. administration of Stx2 promotes a typical pattern of brain injury showing reactive astrocytes and an alteration in the number and activity of nNOS/NADPH-d. According to the functional state of nNOS/NADPH-d and to brain cell morphology data, it could be inferred that the i.c.v. administration of Stx2 leads to either a neurodegenerative or a neuroprotective mechanism in the affected brain areas. The present animal model resembles the encephalopathy developed in Hemolytic Uremic Syndrome (HUS) patients by STEC intoxication.

The blood-brain tumor barrier (BTB) significantly limits delivery of therapeutic concentrations of chemotherapy to brain tumors. A novel approach to selectively increase drug delivery is pharmacologic modulation of signaling molecules that regulate BTB permeability, such as those in cGMP signaling. Here we show that oral administration of sildenafil (Viagra) and vardenafil (Levitra), inhibitors of cGMP-specific PDE5, selectively increased tumor capillary permeability in 9L gliosarcoma-bearing rats with no significant increase in normal brain capillaries. Tumor-bearing rats treated with the chemotherapy agent, adriamycin, in combination with vardenafil survived significantly longer than rats treated with adriamycin alone. The selective increase in tumor capillary permeability appears to be mediated by a selective increase in tumor cGMP levels and increased vesicular transport through tumor capillaries, and could be attenuated by iberiotoxin, a selective inhibitor for calcium-dependent potassium (K(Ca)) channels, that are effectors in cGMP signaling. The effect by sildenafil could be further increased by simultaneously using another BTB "opener", bradykinin. Collectively, this data demonstrates that oral administration of PDE5 inhibitors selectively increases BTB permeability and enhances anti-tumor efficacy for a chemotherapeutic agent. These findings have significant implications for improving delivery of anti-tumor agents to brain tumors.

During development, when inhibitory and excitatory synapses are formed and refined, homeostatic mechanisms act to adjust inhibitory input in order to maintain neural activity within a normal range. As the brain matures, synaptogenesis slows and a relatively stable level of inhibition is achieved. Deficits in inhibitory neurotransmission are associated with increased anxiety-related behavior and drugs that potentiate GABA function, the major inhibitory neurotransmitter in the brain, are effective anxiolytics. These observations raise the possibility that transient perturbations in the activity of neural circuits during development might induce compensatory changes in inhibition that could persist into adulthood and contribute to changes in anxiety-related behavior. To test this hypothesis, we treated mice continuously during the major period of forebrain synaptogenesis (P14-28) with the GABA-A receptor positive modulator diazepam and assessed anxiety-related behavior in adulthood. Control experiments confirmed anxiolytic effects of the drug following one day of treatment and the development of tolerance following two weeks of treatment. When tested in adulthood, one month after the end of treatment, diazepam-treated mice exhibited significantly increased behavioral inhibition in the open-field, elevated-plus maze, and novel object behavioral paradigms. Levels of benzodiazepine binding sites in amygdala and frontal cortex were specifically decreased in diazepam-treated mice demonstrating that homeostatic adjustments in GABA function persist into adulthood. Our results show that increased GABAergic activity can affect the developmental programming of anxiety-related behavior.

Surgical resection of brain tissue is associated with tissue damage at the resection margin. Studies of ischemic brain injury in rodents have shown that administration of L-histidine and thioperamide reduces ischemic tissue loss, in part by inhibition of apoptotic cell death. In this study we tested administration of L-histidine and thioperamide in surgical brain injury in mice. Mice were randomized to one of three groups: Sham surgery (n=18), surgical brain injury without treatment (SBI) (n=33), and surgical brain injury with combined l-histidine and thioperamide treatment (SBI+H) (n=29). Surgical brain injury was induced via right frontal craniotomy with resection of the right frontal lobe. L-histidine (1000 mg/kg) and thioperamide (5 mg/kg) were administered to the SBI+H group immediately following surgical resection. Postoperative assessment included neurobehavioral scores, Evans blue measurement of blood-brain barrier breakdown, brain water content, Nissl histology, and immunohistochemistry for IgG and cleaved caspase 3. Postoperative findings included equivalent neurobehavioral outcomes at 24 and 72 h in the SBI and SBI+H groups, similar histological outcomes between SBI and SBI+H, and similar qualitative staining for cleaved caspase 3. SBI+H had increased BBB breakdown on Evans blue analysis and a trend towards increased brain edema which was significant at 72 h. We conclude that combined treatment with l-histidine and thioperamide leads to increased BBB breakdown and brain edema in surgical brain injury.

Two distinct norepinephrine (NE) transporter mechanisms (uptake 1 and uptake 2) regulate extracellular NE concentrations. An association has been observed between the gradual improvement in patients treated with antidepressants that inhibit the NE transporter (NET/uptake 1) and increases in urinary normetanephrine, the O-methylated NE metabolite and potent inhibitor of uptake 2. These observations led to the hypothesis that increased levels of normetanephrine, and consequently inhibition of uptake 2, may partly be responsible for the clinical efficacy of some antidepressants. To investigate this hypothesis, we employed microdialysis techniques in the rat frontal cortex to monitor extracellular changes in normetanephrine following chronic administration of the clinically effective antidepressant, venlafaxine (a serotonin (5-HT) and NE reuptake inhibitor). We evaluated the neurochemical effects of inhibiting uptake 2 alone, or in conjunction with venlafaxine, on extracellular levels of NE and 5-HT. Chronic venlafaxine administration (14 days, 10 mg/kg, s.c.) elicited significant increases in cortical NE and 5-HT while producing a non-significant trend to increase cortical levels of normetanephrine. Additional studies revealed that combining normetanephrine with venlafaxine (10 mg/kg, i.p.), at a dose of normetanephrine (10 mg/kg, i.p.) that did not produce changes in extracellular levels of NE on its own, potentiated antidepressant-induced increases in extracellular NE. We also report mouse behavioral data involving the tail suspension test that complement the neurochemical observations. These preclinical findings, taken together, suggest that inhibiting both uptake 1 and uptake 2 via venlafaxine and normetanephrine, respectively, elicits a greater increase in cortical levels of NE than inhibiting either transporter alone.

Polyamines are aliphatic amines containing nucleophilic centers that are found in all eukaryotic cells, including brain cells. These compounds determine neuroprotection in experimental models of cerebral ischemia and neurotoxicity. In the current study we investigated the protective effects of spermine, an agonist of the polyamine binding site at the N-methyl-d-aspartate receptor, against the behavioral and neurochemical alterations induced by quinolinic acid. The unilateral intrastriatal injection of quinolinic acid (180 nmol/site into the dorsal striatum) induced stereotypical motor asymmetries, assessed by the open field and elevated body swing tests. Spermine modulated quinolinic acid-induced rotational behavior biphasically. While the previous intrastriatal administration of spermine at the dose of 0.1 nmol/site increased, the administration of spermine at the dose of 10 nmol/site reduced quinolinic acid-induced rotational behavior. Spermine (10 nmol/site) also decreased the contralateral swing behavior induced by quinolinic acid. Furthermore, the effect of 10 nmol of spermine was counteracted by the co-administration of arcaine (10 nmol), a selective antagonist of the polyamine binding site at the N-methyl-d-aspartate receptor. In addition, spermine (10 nmol) protected against quinolinic acid-induced protein carbonylation in the rat striatum, further suggesting an antioxidant role for this polyamine. These results provide evidence that the behavioral and biochemical alterations induced by quinolinic acid are attenuated or prevented by spermine through its interaction with N-methyl-d-aspartate receptor and/or its antioxidant function.

Manganese overexposure in non-human primates and humans causes a neurodegenerative disorder called manganism thought to be related to an accumulation of the metal in the basal ganglia. Here, we assess changes in the concentration of manganese in regions of the brain of a non-human primate (the common marmoset, Callithrix jacchus) following four systemic injections of 30 mg/kg MnCl2 H2O in the tail vein using T1-weighted magnetic resonance imaging (MRI) and compare these to changes in the rat following the same exposure route and dose. The doses were spaced 48 h apart and we imaged the animals 48 h after the final dose. We find that marmosets have significantly larger T1-weighted image enhancements in regions of the brain compared to rats, notably in the basal ganglia and the visual cortex. To confirm this difference across species reflects actual differences in manganese concentrations and not variations in the MRI properties of manganese, we measured the longitudinal relaxivity of manganese (chi1) in the in vivo brain and found no significant species' difference. The high manganese uptake in the marmoset basal ganglia and visual cortex can be explained by CSF-brain transport from the large lateral ventricles and we confirm this route of uptake with time-course MRI during a tail-vein infusion of manganese. There is also high uptake in the substructures of the hippocampus that are adjacent to the ventricles. The large manganese accumulation in these structures on overexposure may be common to all primates, including humans.

In the present paper, we analyzed the effects of hippocampal mGluR1 on the consolidation of a fear-conditioned response and on hippocampal glutamate and GABA concentration in rats subjected to the chemically-induced kindling of seizures. We hypothesized the important role of this glutamate receptor subpopulation in behavioural disturbances accompanying epilepsy. To this end, the behavioural and biochemical effects of selective mGluR1 and 5 receptor ligands were compared in sham and kindled animals (pentylenetetrazol-induced seizures). It was found that despite the fact that the freezing response to the aversively conditioned context was not changed by kindling itself, post-training intrahippocampal (dentate gyrus) injection of AIDA (a mGluR1 antagonist) oppositely influenced rat freezing behaviour in the non-kindled and kindled animals (i.e. the receptor ligand increased and decreased duration of the fear reaction, respectively). Kindling of seizures also enhanced the Glutamate/GABA ratio in the dorsal hippocampus (in vivo microdialysis), indicating an enhancement of excitatory processes in the brain. Altogether, the results showed that kindling of seizures led the potentiation of excitatory processes in the hippocampus, changing the role of the local mGluRs1 population in the conditioned fear learning.

Glutaric acidemia type I (GA-I) is an inherited metabolic disease characterized by striatal degeneration, seizures, and accumulation of glutaric acid (GA). Considering that GA impairs energy metabolism and induces reactive species generation, we investigated whether the acute administration of creatine, an amino acid with antioxidant and ergogenic properties, protects against the seizures and neurochemical alterations (inhibition of Na(+),K(+)-ATPase and increased protein carbonylation) induced by the intrastriatal injection of GA (4 micromol/striatum). We also investigated whether creatine protected against the GA-induced inhibition of glutamate uptake in vitro. Creatine administration (300 mg/kg, p.o.) decreased seizures (evidenced by electrographic changes), protein carbonylation and Na(+),K(+)-ATPase inhibition induced by GA. However, creatine, at a dose capable of fully preventing GA-induced protein carbonylation (50 and 150 mg/kg, p.o.), did not prevent convulsions and Na(+),K(+)-ATPase inhibition, suggesting that the anticonvulsant activity of creatine in this experimental model is not related to its antioxidant action. Creatine also protected against the GA-induced inhibition of l-[(3)H]glutamate uptake in synaptosomes, suggesting that creatine may reduce the deleterious effects of GA by maintaining glutamate uptake in the synaptic cleft. Therefore, considering that creatine significantly attenuates the deleterious effects of GA assessed by behavioral and neurochemical measures, it is plausible to propose the use of this amino acid as an adjuvant therapy in the management of glutaric acidemia.

We have previously reported that intracisternal administration of TGF-beta induces an increase in fat oxidation and that intracisternal administration of anti-TGF-beta antibody partially inhibits an increase in fat oxidation during treadmill running in rats. These results indicate a regulatory role of that TGF-beta in the brain on fat oxidation during exercise. However, it is not clear how TGF-beta in the brain enhance fat oxidation. We hypothesized that TGF-beta in the brain elicits its regulatory effects on fat oxidation via hypothalamic noradrenergic neurons, because some reports have demonstrated the important role of hypothalamic noradrenergic neurons in the regulation of fat oxidation during and after exercise. To examine this hypothesis, we measured the extracellular noradrenaline (NA) levels in the paraventricular hypothalamic nucleus (PVH), ventromedial hypothalamic nucleus (VMH) and lateral hypothalamic area, which are especially important in the regulation of energy metabolism, after intracisternal administration of TGF-beta by using an in vivo brain microdialysis. Microdialysis study revealed that intracisternal administration of TGF-beta3 caused increases in the NA levels in the PVH and VMH. Then, we investigated the impact of impairment of noradrenergic neurons in the PVH and VMH by neurotoxin 6-hydroxydopamine microinjection (NA-lesion) on the action of intracisternal administration of TGF-beta. The NA lesion completely abolished the regulatory effect of TGF-beta on fat oxidation. These results suggest that TGF-beta in the brain enhances fat oxidation via noradrenergic neurons in the PVH and VMH.

In the present work, effects of maternal administration of para-chlorophenylalanine (PCPA), a serotonin synthesis inhibitor, on behavior of adult offspring were studied. Pregnant rats were injected intraperitoneally with PCPA (200/100/100/50 mg/kg) either on the gestational days (GD) 8-11 or 14-17, or with vehicle at the same days. Behavioral parameters, in an open field, the Porsolt forced swim test and the Morris water maze test were evaluated at the age of 3-3.5 months in the male and female offspring. The prenatal PCPA increased activity in an open field in the offspring treated on either GD 8-11 or 14-17. The highest levels of the activity were revealed in the male and female offspring treated on GD 14-17. Besides, the PCPA treatment on GD 8-11 or 14-17 facilitated the intersession habituation of activity to repeated exposures to an open field in the male offspring. Both male and female offspring treated on GD 14-17 showed an increased immobility in the Porsolt forced swim test and a significant learning impairment in the Morris water maze. Thus, it has been shown that administration of PCPA to pregnant rats might cause significant changes in the adult offspring behavior. These results provide further evidence that unfavorable influence may have more adverse effects on the behavioral development of rats when exposed during the final trimester of pregnancy than during the second trimester.

Brain glutamatergic system is involved in synaptic plasticity as a base for learning and neural development. This study investigated the effects of neonatal and adult chronic antagonism of N-methyl-d-aspartate (NMDA) receptors, a subtype of glutamate receptors, on learning and/or memory. Rats were trained in the radial-maze learning, which is known as a measure of spatial working memory capacities, in adulthood after neonatal or adult repeated treatment of MK-801 (dizocilpine; 5-methyl-10,11-dihydro-5H-dibenzo[a,d]-cyclohepten-5,10-imine), a non-competitive antagonist, or neonatal repeated treatment of CGS 19755 (cis-4-phosphonomethyl-2-piperadine carboxilic acid), a competitive antagonist. Neonatal repeated treatment of MK-801 or CGS 19755 markedly impaired the radial-arm maze learning. In addition, the treatment altered activities differently in the radial-maze and in the open-field. On the other hand, adult repeated treatment with MK-801 affected neither the radial-maze learning nor activities. Results suggest that chronic blockade of NMDA receptors in a neonatal stage may produce long-lasting deteriorative effects on spatial working memory in adulthood.

Explosive running is a reliable initial component of audiogenic seizures (AS) induced by acoustic stimulation in genetically prone rodents. This profound locomotor activation is usually considered as a convulsive manifestation of AS although some studies attribute running to a panic-like response. Increase in central histamine activity has been shown to suppress clonic and tonic seizures. The present study examined the involvement of histaminergic mechanisms in the expression of running component of AS. Metoprine, an inhibitor of histamine-N-methyltransferase, was used to increase brain histamine level. Running was induced 4 and 24 h after intraperitoneal injection of metoprine or vehicle in rats of different strains. A brief sound stimulation elicited running followed by clonic-tonic convulsions in Krushinsky-Molodkina (KM) rats or running alone in AS-prone Wistar and WAG/Rij rats. In KM rats, metoprine exerted opposite effects on the main phases of AS. It increased the duration of running and decreased the duration and severity of clonic-tonic convulsions. In Wistar rats, metoprine produced a remarkable aggravation of running leading to its 2- to 3-fold prolongation. In WAG/Rij rats with mixed seizures (absence and audiogenic), the drug caused either aggravation or suppression of running behavior. These results suggest specific role for histaminergic system in the expression of behavioral components of AS. Suppressive role of histamine in clonic-tonic seizures is associated with facilitation of running suggesting specific effects of histamine on brainstem neuronal networks underlying these phases of AS. Possible roles of histaminergic mechanisms in seizure, motor and aversive aspects of sound-induced running are discussed.

Drugs of abuse induce alterations in cytoskeletal and cytoskeleton associated genes in several brain areas. We have previously shown that acute MDMA regulates the mRNA level of Rnd3, a Rho GTPase involved in actin cytoskeleton regulation, in mice striatum. In this study we investigated the effects of single administration of cocaine, another psychostimulant with a slightly different mechanism of action, on the mRNA levels of the three members of the Rnd genes family (Rnd1, Rnd2 and Rnd3). Mice were treated with either MDMA (9 mg/kg) or cocaine (20 mg/jg) and brain samples (i.e. hippocampus, striatum and prefrontal cortex) were processed for quantitative real-time PCR assay 1, 2, 4 and 6 h after the injections. The expression level of Rnd2 was differentially affected depending on the drug, brain area and time point after injection. Interestingly the two drugs up-regulate Rnd3 gene expression in the three structures tested with some differences in the timing. The effects of MDMA on Rnd3 appear earlier in the hippocampus as compared to cocaine, while it is the opposite in the prefrontal cortex. However, in the dorsal striatum, the two drugs induce an early and significant up-regulation of Rnd3 expression that is longer-lasting in the case of MDMA. In the case of cocaine contrarily to what was observed with MDMA, this modulation could not be blocked with the ERK activation inhibitor SL327 suggesting that the two drugs lead to the same effect on Rnd3 by two distinct pathways.

Cocaine, amphetamines and other psychostimulants inhibit synaptic dopamine uptake by interfering with dopamine transporter (DAT) function. The resultant potentiation of dopaminergic neurotransmission is associated with psychostimulant addiction. Fluctuations in dopamine uptake inhibition potency (DUIP) were observed for classical DAT blockers including cocaine, mazindol, methylphenidate (Ritalintrade mark) and benztropine in CHO cells expressing wild type DAT; cocaine potency also decreased in DAT-expressing non-neuronal COS-7 cells and neuronal N2A neuroblastoma cells. In contrast, the DAT substrate (+)-amphetamine did not display this DUIP fluctuation. In parallel experiments, no fluctuation was observed for the apparent binding affinities of these 5 drugs. The DUIP decrease appeared to correlate with an increase in cell surface DAT expression level, as measured by B(max) values and confocal microscopy. The fact that the DUIP profile of amphetamine diverged from that of the classical DAT blockers is consistent with the idea of fundamental differences between the mechanisms of abused psychostimulant DAT substrates and inhibitors. Identification of the cellular factors that underlie the DAT inhibitor DUIP fluctuation phenomenon may be relevant to anti-psychostimulant drug discovery efforts.

We previously reported that brief (1 h), but not extended (6 h), daily access to cocaine results in a sensitized locomotor response to cocaine and in elevated c-Fos immunoreactivity and DAT binding in the nucleus accumbens (N.Acc) core. In order to better our understanding of the neural adaptations mediating the transition from controlled drug use to addiction, the current experiments were set to further explore the neural adaptations resulting from these two access conditions. Rats received either brief daily access to saline or cocaine, or brief daily access followed by extended daily access to cocaine. Subjects were then sacrificed either 20 min, or 14 or 60 days, after the last self-administration session. Samples of the ventral tegmental area (VTA), N.Acc core and shell, dorsal striatum, and medial prefrontal cortex (mPFC) were taken for analysis of D1 ([3H]SCH-23390), D2 ([3H]Spiperone), and NMDA ([3H]MK-801) receptor binding (using the method of receptor autoradiography). At 20 min into withdrawal, D2 receptors were elevated and NMDA receptors were reduced in the mPFC of the brief access animals while D1 receptors were elevated in the N.Acc shell of the extended access animals, compared to saline controls. D2 receptors were reduced in the N.Acc shell of the brief access animals compared to saline controls after 14 days, and compared to extended access animals after 60 days of withdrawal. In summary, extended access to cocaine resulted in only transient changes in D1 receptors binding. These results suggest that the development of compulsive drug use is largely unrelated to changes in total binding of D2 or NMDA receptors.

In order to clarify the mechanism of Ginkgo biloba extract (GBE) on learning and memory, we studied the effect of GBE on spatial memory deficits induced by diphenhydramine, pyrilamine and scopolamine using the eight-arm radial maze performance of rats, in comparison with donepezil. Total error (TE), reference memory error (RME) and working memory error (WME) were used as indices of spatial memory deficits. Both GBE and donepezil caused a potent antagonistic effect on the increase in TE, RME and WME induced by diphenhydramine. GBE and donepezil also antagonized scopolamine-induced spatial memory deficits. Although the antagonistic effect of GBE on pyrilamine-induced spatial memory deficits was weak, a significant difference was observed with TE and WME. However, donepezil caused no antagonistic effect on pyrilamine-induced memory deficits. From these findings, we concluded that the effects of GBE are mainly contributable to cholinergic activity and perhaps partly due to a histaminergic mechanism.

Both preclinical and clinical studies have shown sexually dimorphic patterns in behavioral responses to cocaine in all phases of the cocaine addiction process (induction, maintenance, and relapse). Thus, a clear picture is emerging which suggests that the biological basis of sex-specific differences in cocaine addiction resides in the disparate regulation of the CNS by male and female gonadal hormones. This review discusses the role that gonadal hormones play in these sexually dimorphic patterns of behavioral responses to cocaine.

The mechanism of ethanol, morphine, methamphetamine (MAP), and nicotine-induced ascorbic acid (AA) release in striatum, and nucleus accumbens (NAc) is not well understood. Our previous study showed that the glutamatergic system was involved in the addictive drug-induced AA release in NAc and striatum. Furthermore, frontal decortication eliminates drug-induced ascorbic acid release in the striatum but not in the NAc. In the present study, the roles of the hippocampus in drug-induced AA release in the striatum and NAc were studied by using microdialysis coupled to high performance liquid chromatography with electrochemical detection (HPLC-ECD). Ethanol (3.0 g/kg, i.p.), methamphetamine (3.0 mg/kg, i.p.), and nicotine (1.5 mg/kg, i.p.) significantly stimulated AA release in the striatum and NAc, respectively. Morphine (20 mg/kg, i.p.) significantly stimulated AA release in the striatum, but not in the NAc. After hippocampal lesion by kainic acid, AA release induced by ethanol, methamphetamine, and nicotine could be eliminated in NAc, but not in the striatum. These results suggest that the hippocampus might be a common and necessary area in addictive drug-induced AA release in the NAc, which also imply that different pathways might be involved in drug-induced AA release in the striatum and the NAc of the rats.

The brain-derived neurotrophic factor (BDNF) gene is a candidate gene for influencing the clinical response to treatment with antidepressants. The purpose of this study was to determine the relationship between the Val66Met polymorphism in the BNDF gene and the response to citalopram in a Korean population with major depressive disorder (MDD). Citalopram was administered for 8 weeks to the 83 patients who completed this study. We found that the genotype, allele, and allele-carrier distributions for the Val66Met polymorphism differed significantly between responders (Rp) and nonresponders (Non-Rp). The frequency of M-allele carriers (VM+MM) was higher in Rp than in Non-Rp (chi(2)=8.926, p=0.003, OR=4.375, 95%CI=1.609-11.892), as was the M-allele frequency (chi(2)=6.879, p=0.009, OR=2.500, 95%CI=1.249-5.005). There were also significant differences in the core (p=0.012) and activity (p=0.008) scores. Patients carrying the M-allele had a lower score. Also, patients carrying the M-allele tended to have lower psychic anxiety (p=0.072). The percentage change in the total HAM-D score was higher for M-allele carriers (VM+MM allele) than for noncarriers (p=0.034) after 8 weeks of medication. We found that the genotype, allele, and allele-carrier distributions did not differ significantly between MDD patients and normal controls. These results suggest that the Val66Met polymorphism of BDNF is associated with citalopram efficacy, with M-allele carriers responding better to citalopram treatment. Moreover, the Val66Met polymorphism was correlated with improvements in core, activity, and psychic anxiety symptoms.

While cocaine's interaction with the dopamine (DA) transporter and subsequent increase in DA transmission are usually considered key factors responsible for its locomotor stimulatory and reinforcing properties, many centrally mediated physiological and psychoemotional effects of cocaine are resistant to DA receptor blockade, suggesting the importance of other non-DA mechanisms. To explore the role of cocaine's interaction with Na+ channels, rats were used to compare locomotor stimulatory and temperature (NAcc, temporal muscle and skin) effects of repeated iv injections of cocaine (1 mg/kg) with those induced by procaine (PRO 5 mg/kg), a short-acting local anesthetic with negligible effect on the DA transporter, and cocaine methiodide (COC-MET 1.31 mg/kg), a quaternary cocaine derivative that is unable to cross the blood-brain barrier. While PRO, unlike cocaine, did not induce locomotor activation, it mimicked cocaine in its ability to increase brain temperature following the initial injection and to induce biphasic, down-up fluctuations following repeated injections. This similarity suggests that both these effects of cocaine may be driven by its action on Na+ channels, a common action of both drugs. While COC-MET also did not affect locomotor activity, it shared with cocaine and PRO their ability to increase brain temperature but failed to induce temperature decreases after repeated injections. These findings point toward activation of peripheral Na+ channels as the primary mechanism of rapid excitatory effects of cocaine and inhibition of centrally located Na+ channels as the primary mechanism for transient inhibitory effects of cocaine. DA receptor blockade (SCH23390+eticlopride) fully eliminated locomotor stimulatory and temperature-increasing effects of cocaine, but its temperature-decreasing effects remained intact. Surprisingly, DA receptor blockade also altered the temperature fluctuations caused by PRO and COC-MET, suggesting that some of the central effects triggered via Na+ channels are in fact DA-dependent. Finally, repeated administration of PRO to animals that had previous cocaine experience led to conditioned locomotion and potentiated temperature-increasing effects of this drug. It appears, therefore, that, in addition to the central effects of cocaine mediated via interaction with the DA transporter and potentiation of DA uptake, interaction with peripheral and central Na+ channels is important for the initial physiological and, perhaps, affective effects of cocaine, likely contributing to the unique abuse potential of this drug.