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[Purpose] Most monotherapies available against glioblastoma multiforme (GBM) target individual hallmarks of this aggressive brain tumor with minimal success. In this article, we propose a therapeutic strategy using coenzyme Q10 (CoQ10) as a pleiotropic factor that crosses the blood–brain barrier and accumulates in cell membranes acting as an antioxidant, and in mitochondrial membranes as a regulator of cell bioenergetics and gene expression., [Methods] Xenografts of U251 cells in nu/nu mice were used to assay tumor growth, hypoxia, angiogenesis, and inflammation. An orthotopic model was used to explore microglial infiltration, tumor growth, and invasion into the brain parenchyma. Cell proliferation, migration, invasion, proteome remodeling, and secretome were assayed in vitro. Conditioned media were used to assay angiogenesis, monocyte chemoattraction, and differentiation into macrophages in vitro., [Results] CoQ10 treatment decreased tumor volume in xenografts and orthotopic models, although its effect on tumor cell proliferation was not direct. Tumors from mice treated with CoQ10 were less hypoxic and vascularized, having less infiltration from inflammatory cells. Treatment-induced downregulation of HIF-1α and NF-kB led to a complete remodeling of the tumor cells proteome and secretome, impacting angiogenesis, monocyte infiltration, and their differentiation into macrophages. Besides, tumor cell migration and invasion were drastically restricted by mechanisms involving modulation of the actin cytoskeleton and downregulation of matrix metalloproteases (MMPs)., [Conclusions] CoQ10 has a pleiotropic effect on GBM growth, targeting several hallmarks simultaneously. Thus, its integration into current treatments of this fatal disease should be considered., This work has been supported by Grants 220020351 (James S. MacDonnell Foundation), GE20112221 (Universidad de Castilla-La Mancha), PPII-2014–010-P (Junta de Comunidades de Castilla-La Mancha), MTM2015-71200-R (MINECO-FEDER), and SAF2016-79311-R (MINECO-FEDER).

Most monotherapies available against glioblastoma multiforme (GBM) target individual hallmarks of this aggressive brain tumor with minimal success. In this article, we propose a therapeutic strategy using coenzyme QXenografts of U251 cells in nu/nu mice were used to assay tumor growth, hypoxia, angiogenesis, and inflammation. An orthotopic model was used to explore microglial infiltration, tumor growth, and invasion into the brain parenchyma. Cell proliferation, migration, invasion, proteome remodeling, and secretome were assayed in vitro. Conditioned media were used to assay angiogenesis, monocyte chemoattraction, and differentiation into macrophages in vitro.CoQCoQ

The amyloid β peptide (Aβ) is a central player in the neuropathology of Alzheimer’s disease (AD). The alteration of Aβ homeostasis may impact the fine-tuning of cell signaling from the very beginning of the disease, when amyloid plaque is not deposited yet. For this reason, primary culture of rat cortical neurons was exposed to Aβ25-35, a non-oligomerizable form of Aβ. Cell viability, metabotropic glutamate receptors (mGluR) and adenosine receptors (AR) expression and signalling were assessed. Aβ25-35 increased mGluR density and affinity, mainly due to a higher gene expression and protein presence of Group I mGluR (mGluR1 and mGluR5) in the membrane of cortical neurons. Intriguingly, the main effector of group I mGluR, the phospholipase C β1 isoform, was less responsive. Also, the inhibitory action of group II and group III mGluR on adenylate cyclase (AC) activity was unaltered or increased, respectively. Interestingly, pre-treatment of cortical neurons with an antagonist of group I mGluR reduced the Aβ25-35-induced cell death. Besides, Aβ25-35 increased the density of A1R and A2AR, along with an increase in their gene expression. However, while A1R-mediated AC inhibition was increased, the A2AR-mediated stimulation of AC remained unchanged. Therefore, one of the early events that takes place after Aβ25-35 exposure is the up-regulation of adenosine A1R, A2AR, and group I mGluR, and the different impacts on their corresponding signaling pathways. These results emphasize the importance of deciphering the early events and the possible involvement of metabotropic glutamate and adenosine receptors in AD physiopathology.

Although the pharmacological and behavioural interactions between cocaine and alcohol are well established, less is known about how polyconsumption of these drugs affects the neurotransmitter systems involved in their psychoactive effects and in particular, in the process of addiction. Here, rats of both sexes at two stages of development were studied under a chronic regime of intravenous cocaine and/or alcohol administration. Brain samples from the medial prefrontal cortex, nucleus accumbens, hippocampus and amygdala were extracted to analyse the mRNA expression of genes encoding subunits of the GABA, NMDA and AMPA receptors, as well as the expression of the CB1 receptor, and that of enzymes related to the biosynthesis and degradation of endocannabinoids. Moreover, two synaptic scaffold proteins related to GABA and NMDA receptors, gephyrin and PSD-95, were quantified in Western blots. Significant interactions between cocaine and alcohol were common, affecting the GABAergic and endocannabinoid systems in the medial prefrontal cortex and amygdala of young adults, whereas such interactions were evident in the glutamatergic and endocannabinoid systems in adults, as well as a more pronounced sex effect. Significant interactions between these drugs affecting the scaffold proteins were evident in the medial prefrontal cortex and nucleus accumbens of young adults, and in the nucleus accumbens and amygdala of adults, but not in the hippocampus. These results highlight the importance of considering the interactions between cocaine and alcohol on neurotransmitter systems in the context of polyconsumption, specifically when treating problems of abuse of these two substances.

Objective The aim of this study was to explore the influence of an enrolled degree course on health and eating habits in a population of Spanish university students (17–26 y of age). Methods A cross-sectional observational study was carried out with 648 students. Volunteers were stratified into biomedical (medicine and nursing, 48%) and non-biomedical students (other fields of study, 52%). Data were collected using previously self-reported questionnaires focused on anthropometric and sociodemographic profile, lifestyle practices, body image perception, health consciousness, eating habits, physical activity, and food addiction. Mann–Whitney U tests and Pearson's χ2 tests were applied to identify associations between the two groups. Results Self-reported body mass index was higher for the non-biomedical group (22.1 ± 3.1 versus 23 ± 5 kg/m2; P Conclusions Healthier lifestyle factors cluster into the biomedical group in various components of the study, except food addiction where no differences were observed. The data presented here suggest the necessity to develop health promotion strategies targeting university students.

Electromagnetically driven drug delivery systems stand out among stimulus-responsive materials due to their ability to release cargo on demand by remote stimulation, such as light, near infrared (NIR) or microwave (MW) radiation. MW-responsive soft materials, such as hydrogels, generally operate at 2.45 GHz frequencies, which usually involves rapid overheating of the scaffold and may affect tissue surrounding the target location. In contrast, 915 MHz MW penetrate deeper tissues and are less prone to induce rapid overheating. In order to circumvent these limitations, we present here for the first time a graphene-based hydrogel that is responsive to MW irradiation of ν = 915 MHz. This system is a candidate soft scaffold to deliver a model hydrophobic drug. The graphene present in the hydrogel acts as a heat-sink and avoids overheating of the scaffold upon MW irradiation. In addition, the microwave trigger stimulates the in vitro delivery of the model drug, thus suggesting a remote and deeppenetrating means to deliver a drug from a delivery reservoir. Moreover, the MW-triggered release of drug was observed to be enhanced under acidic conditions, where the swelling state is maximum due to the swelling-induced pH-responsiveness of the hydrogel. The hybrid composite described here is a harmless means to deliver remotely a hydrophobic drug on demand with a MW source of 915 MHz. Potential uses in biomedical applications were evaluated by cytotoxicity tests.

Low therapeutic adherence is a concern for health professionals as it decreases therapeutic efficiency while increasing costs, especially in elderly populations. To increase therapeutic adherence in elderly populations, the technology applied in the medical devices that are used must be adapted to improve usability. This paper outlines the rationale behind, and methods applied to assess the usability of, ACHO (Assistant on Care and Health Offline), a voice assistant that provides elderly patients with reminders of medical appointments to attend and when they need to take their medication. This work is a descriptive, cross-sectional, observational study, and will include a three-phase (analysis, testing and refinement) multidimensional usability analysis of an initial prototype, in the setting of a user-driven Living Lab, which enables the needs and characteristics of the end users to be identified and incorporated into the prototype with each iteration, in which a multidisciplinary team of researchers and users will participate as co-creators. This methodology will allow us to develop a better prototype, increasing usability and, thus, increasing therapeutic adherence.

Tools for online collaboration are becoming increasingly prevalent in recent years. Certain characteristics of these tools encourage this proliferation: they are easy to use, always available, allow knowledge to be built collaboratively and disseminated quickly through social networks, and are usually free of charge. In this context, blogs are becoming increasingly important in the field of health as digital newspapers and magazines that support a large number of multimedia formats. The possibility to subscribe to blogs and their availability in formats adaptable to mobile devices mean their content can be taken anywhere. Although the use of blogs is well-established among Health Science professionals, their use among university professors as a component of the teaching strategies in these disciplines is much less common, and thus the benefits, risks and limitations of using blogging as a pedagogical tool are poorly understood. In this preliminary evaluation of a pedagogy, a public WordPress-based blog was developed for the Nutrition and Dietetics module of the undergraduate course in Nursing at the University of Castilla-La Mancha (Spain). This was primarily intended as way to use ICT to increase the level of student engagement and interest in learning the subject, but also as a way to introduce future health professionals to the world of blogging. This paper describes our experiences with this pedagogical project and discusses the advantages and disadvantages of the use of blogs in university Health Sciences teaching. Incorporating this tool into teaching methodologies takes advantages of the theoretical possibilities it offers, which include crucial aspects such as developing critical thinking, acquiring knowledge, answering questions from students, and enabling new mechanisms to develop the skills that must be acquired. However, the challenges and inconveniences are also highlighted; these are principally the lack of motivation and the low participation of the students. By analysing the outcomes of this preliminary evaluation of a pedagogy, it is concluded that blogs are a very useful tool, although it is suggested that the literature shows a certain bias toward the publication of successful trials.

Relapse into drug use is a major problem faced by recovering addicts. In humans, an intensification of the desire for the drug induced by environmental cues-incubation of drug craving-has been observed. In rodents, this phenomenon has been modeled by studying drug seeking under extinction after different times of drug withdrawal (or using a natural reinforcer). Although much progress has been made, an integrated approach simultaneously studying different drug classes and natural reward and examining different brain regions is lacking. Lewis rats were used to study the effects of cocaine, heroin, and sucrose seeking incubation on six key brain regions: the nucleus accumbens shell/core, central/basolateral amygdala, and dorsomedial/ventromedial prefrontal cortex. We analyzed PSD95 and gephyrin protein levels, gene expression of glutamatergic, GABAergic and endocannabinoid elements, and amino acid transmitter levels. The relationships between the areas studied were examined by Structural Equation Modelling. Pathways from medial prefrontal cortex and basolateral complex of the amygdala to central nucleus of the amygdala, but not to the nucleus accumbens, were identified as common elements involved in the incubation phenomenon for different substances. These results suggest a key role for the central nucleus of amygdala and its cortical and amygdalar afferences in the incubation phenomenon, and we suggest that by virtue of its regulatory effects on glutamatergic and GABAergic dynamics within amygdalar circuits, the endocannabinoid system might be a potential target to develop medications that are effective in the context of relapse.

Adenosine receptors (AR) are a family of G-protein coupled receptors, comprised of four members, named A1, A2A, A2B, and A3 receptors, found widely distributed in almost all human body tissues and organs. To date, they are known to participate in a large variety of physiopathological responses, which include vasodilation, pain, and inflammation. In particular, in the central nervous system (CNS), adenosine acts as a neuromodulator, exerting different functions depending on the type of AR and consequent cellular signaling involved. In terms of molecular pathways and second messengers involved, A1 and A3 receptors inhibit adenylyl cyclase (AC), through Gi/o proteins, while A2A and A2B receptors stimulate it through Gs proteins. In the CNS, A1 receptors are widely distributed in the cortex, hippocampus, and cerebellum, A2A receptors are localized mainly in the striatum and olfactory bulb, while A2B and A3 receptors are found at low levels of expression. In addition, AR are able to form heteromers, both among themselves (e.g., A1/A2A), as well as with other subtypes (e.g., A2A/D2), opening a whole range of possibilities in the field of the pharmacology of AR. Nowadays, we know that adenosine, by acting on adenosine A1 and A2A receptors, is known to antagonistically modulate dopaminergic neurotransmission and therefore reward systems, being A1 receptors colocalized in heteromeric complexes with D1 receptors, and A2A receptors with D2 receptors. This review documents the present state of knowledge of the contribution of AR, particularly A1 and A2A, to psychostimulants-mediated effects, including locomotor activity, discrimination, seeking and reward, and discuss their therapeutic relevance to psychostimulant addiction. Studies presented in this review reinforce the potential of A1 agonists as an effective strategy to counteract psychostimulant-induced effects. Furthermore, different experimental data support the hypothesis that A2A/D2 heterodimers are partly responsible for the psychomotor and reinforcing effects of psychostimulant drugs, such as cocaine and amphetamine, and the stimulation of A2A receptor is proposed as a potential therapeutic target for the treatment of drug addiction. The overall analysis of presented data provide evidence that excitatory modulation of A1 and A2A receptors constitute promising tools to counteract psychostimulants addiction.

It has previously been shown that during gestation, the mother's brain has an increase in glial fibrillary acidic protein (GFAP)-immunoreactivity (-ir) and a decrease in the mRNA level of A1 adenosine receptor. Little is known about the A2A adenosine receptor in the maternal brain, and whether caffeine consumption throughout gestational period modifies GFAP and adenosine receptor density in specific brain areas. This study was undertaken to investigate the protein density of GFAP and adenosine receptors (A1 and A2A subtypes) in different regions of pregnant rat brain and the possible effect of caffeine on these proteins.For this purpose, we examined the GFAP-, A1- and A2A-ir in the cingulate cortex (Cg2), dentate gyrus (DG), medial preoptic area (mPOA), secondary somatosensory cortex (S2), and striatum (Str) of pregnant Wistar rats (drug-free tap water or water with 1g/L diluted caffeine).We show a consistent and highly significant reduction of GFAP-ir in caffeine-treated pregnant rats in most of the areas analyzed. Our data demonstrate that caffeine consumption induces a significant increase of A2A-ir in Str. Concerning A1 receptor, the observed changes are dependent on the region analyzed; this receptor density is increased in Cg2, DG, and mPOA and decreased in the somatosensory cortex and Str. The results were confirmed by Western blotting.Our results suggest that chronic caffeine exposure could modify the physiolological situation of gestation by a reorganization of the neural circuits and the adenosine neuromodulator system.

Glutamate is an excitatory neurotransmitter implicated in learning and memory processes, but at high concentrations it acts as an excitotoxin causing degeneration and neuronal death. The aim of this work was to determine the excitotoxic effect of glutamate and the regulation of metabotropic glutamate receptors (mGluR) during excitotoxicity in neurons and C6 glioma cells. Results show that glutamate causes excitotoxic damage only in cortical neurons. Loss of cell viability in neurons was glutamate concentration- and time-dependent. Total mGluR levels were significantly reduced in these cells when exposed to glutamate. However, in C6 cells, which have been used as a model of glial cells, these receptors were regulated in a biphasic manner, decreased after 6 h, and increased after 24/48 h of treatment. Results show a cell dependent mGluR regulation by glutamate exposure which could mediate the vulnerability or not to glutamate mediated excitotoxicity.

10 pages, 5 figures.-- PMID: 17467187 [PubMed].-- Printed version published Jun 8, 2007.-- Supporting information (Suppl. tables S1-S3) available at: http://dx.doi.org/10.1016/j.neuroscience.2007.03.017, The CB1 cannabinoid receptors modulate the addictive processes associated with different drugs of abuse, including psychostimulants. Mice lacking CB1 receptors exhibit an important attenuation of the reinforcing responses produced by cocaine in an operant self-administration paradigm. We have investigated the effect of chronic cocaine treatment on dendrite structure and spine density of the principal cortical neuron, the pyramidal neuron, in CB1 knockout mice and wild type littermates. Layer III pyramidal cells of the motor cortex were injected intracellularly in fixed cortical slices and their morphometric parameters analyzed. Under basal conditions, the field area of the dendritic arbors was more extensive and dendritic spine density was higher in wild type mice than in CB1 knockout mice. Chronic treatment of cocaine diminished the size and length of the basal dendrites and spine density on pyramidal cells from wild type mice. However, the total number of spines in the pyramidal cells of CB1 knockout mice augmented slightly following chronic cocaine treatment, although no changes in the morphology of the dendritic arbor were observed. Our data demonstrate that microanatomy and synaptic connectivity are affected by cocaine, the magnitude and nature of these changes depend on the presence of CB1 receptors., This work was supported by the "Ministerio de Ciencia y Tecnología" (BFI 2003–02745 and BFU2006-13395 to J.D., SAF2004/0568 to O.V.; BFU2004/00920BFI to R.M., and GEN2003-20651-C06-06 to J.D. and R.M.), the European Community (GENADDICT OJ2004/C164 No. 005166 and NEWMOOD LSHM-CT-2003 5003474), and the National Institutes of Health (grant 1RO1DA016768). I.B.-Y. was supported by the MEC (AP2001-0671).

© 2013 The Author. Chronic exposure to cocaine induces modifications to neurons in the brain regions involved in addiction. Hence, we evaluated cocaine-induced changes in the hippocampal CA1 field in Fischer 344 (F344) and Lewis (LEW) rats, 2 strains that have been widely used to study genetic predisposition to drug addiction, by combining intracellular Lucifer yellow injection with confocal microscopy reconstruction of labeled neurons. Specifically, we examined the effects of cocaine self-administration on the structure, size, and branching complexity of the apical dendrites of CA1 pyramidal neurons. In addition, we quantified spine density in the collaterals of the apical dendritic arbors of these neurons. We found differences between these strains in several morphological parameters. For example, CA1 apical dendrites were more branched and complex in LEW than in F344 rats, while the spine density in the collateral dendrites of the apical dendritic arbors was greater in F344 rats. Interestingly, cocaine self-administration in LEW rats augmented the spine density, an effect that was not observed in the F344 strain. These results reveal significant structural differences in CA1 pyramidal cells between these strains and indicate that cocaine self-administration has a distinct effect on neuron morphology in the hippocampus of rats with different genetic backgrounds.

The biology underlying epileptic brain activity in humans is not well understood and likely depends on changes in gene expression. We performed a microarray transcriptome profiling of 12 anterolateral temporal cortical samples originating from five individuals who suffered with temporal lobe epilepsy for at least 10 years. Prior to partial lobectomy, intraoperative electrocorticography was performed on the cortical surface of each patient. These recordings showed characteristic differences in frequency and amplitude that were defined as “spiking” (abnormal) or “non-spiking” (normal). Between the transcriptome of the two sample groups, transferrin (TF) was the most differentially expressed gene. Furthermore, gene expression profiling also revealed a downregulation of multiple GABA system-related genes (GABRA5, GABRB3, ABAT) in the spiking samples and an upregulation of oligodendrocyte and lipid metabolism transcripts (MOG, CA2, CNP, SCD, PLP1, FA2H, ABCA2). In addition, several transcripts related to the classical MAPK cascade showed expression level alterations between the spiking and non-spiking samples (G3BP2, MAPK1, PRKAR1A, and MAP4K4). Out of 12 genes chosen for verification by RT qPCR, 9 showed significant expression changes in the microarray-predicted direction. Furthermore, the microarray and qPCR data were highly correlated (r = 0.98; P

Addiction involves long-lasting maladaptive changes including development of disruptive drug-stimuli associations. Nicotine-induced neuroplasticity underlies the development of tobacco addiction but also, in regions such as the hippocampus, the ability of this drug to enhance cognitive capabilities. Here, we propose that the genetic locus of susceptibility to nicotine addiction, the CHRNA5/A3/B4 gene cluster, encoding the ?5, ?3 and ?4 subunits of the nicotinic acetylcholine receptors (nAChRs), may influence nicotine-induced neuroadaptations. We have used transgenic mice overexpressing the human cluster (TgCHRNA5/A3/B4) to investigate hippocampal structure and function in genetically susceptible individuals. TgCHRNA5/A3/B4 mice presented a marked reduction in the dendrite complexity of CA1 hippocampal pyramidal neurons along with an increased dendritic spine density. In addition, TgCHRNA5/A3/B4 exhibited increased VGLUT1/VGAT ratio in the CA1 region, suggesting an excitatory/inhibitory imbalance. These hippocampal alterations were accompanied by a significant impairment in short-term novelty recognition memory. Interestingly, chronic infusion of nicotine (3.25 mg/kg/d for 7 d) was able to rescue the reduced dendritic complexity, the excitatory/inhibitory imbalance and the cognitive impairment in TgCHRNA5/A3/B4. Our results suggest that chronic nicotine treatment may represent a compensatory strategy in individuals with altered expression of the CHRNA5/A3/B4 region. The laboratory of Mara Dierssen is supported by Departament d'Universitats, Recerca i Societat de la Informació (Grups consolidats 09 2009SGR1313). This work was supported by Grants SAF2010-16427, SAF2007-31093-E, and FIS (PI 082038); Marató TV3; the Jerome Lejeune, Koplowitz, FRAXA and Areces Foundations; and the European Union (CureFXS ERare-EU/FIS PS09102673, EU- Era NET Neuron. FOOD for THOUGHT F4T). The laboratory of Mairena Martín is supported by Ministerio de Economía y Competitividad (BFU2011-23034). The Centro de Investigación Biomédica en Red de Enfermedades Raras is an initiative of the Instituto de Salud Carlos III. The laboratory of María V. Sánchez is supported by Ministerio de Economía y Competitividad (BFU2011-27094)

The gene encoding the dual-specificity tyrosine-regulated kinase DYRK1A maps to the chromosomal segment HSA21q22.2, which lies within the Down syndrome critical region. The reduction in brain size and behavioral defects observed in mice lacking one copy of the murine homologue Dyrk1A (Dyrk1A+/-) support the idea that this kinase may be involved in monosomy 21 associated mental retardation. However, the structural basis of these behavioral defects remains unclear. In the present work, we have analyzed the microstructure of cortical circuitry in the Dyrk1A+/- mouse and control littermates by intracellular injection of Lucifer Yellow in fixed cortical tissue. We found that labeled pyramidal cells were considerably smaller, less branched and less spinous in the cortex of Dyrk1A+/- mice than in control littermates. These results suggest that Dyrk1A influences the size and complexity of pyramidal cells, and thus their capability to integrate information.

Double bouquet cells (DBCs) are neocortical gamma-aminobutyric acid (GABA)ergic interneurons characterized by the vertical bundling of its axon, which are generally termed "bundles" or "horse-tails." Using immunocytochemistry for the calcium binding protein calbindin, we have analyzed the morphology, density, and distribution of DBC horse-tails in different cortical areas of the human cortex (Brodmann's areas 10, 4, 3b, 22, 18, and 17). Although DBC horse-tails were very numerous and regularly distributed in all cortical areas, variations were observed both in terms of morphology and density. We distinguished two major classes of DBC horse-tails: the thicker complex type (type I) that had more axon collaterals; and the simple type (type II). The density of DBC horse-tails was significantly higher in areas 17, 18, 22, and 4 than in areas 3b and 10. Moreover, the proportion of type I and type II DBC horse-tails varied in the cortical areas studied. We also examined the distribution of DBC horse-tails in frontal, parietal, and occipital areas of different mammalian species. We found DBCs to be present in carnivores but not in rodents, lagomorphs, or artiodactyls. In carnivores, relatively few DBC horse-tails can be identified and they were generally found in the occipital cortex. Therefore, there is significant variability in the morphology and distribution of DBC horse-tails in different species and cortical areas. We conclude that, although these interneurons may be an important element in the organization of cortical microcolumns in primates, this is not the case in other mammalian species.

Impairment of GABA-mediated inhibition is one of the main hypotheses invoked to explain seizure activity, both in experimental models and in human epilepsy. We have studied the distribution and the neurochemical characteristics of certain GABAergic circuits in the normal and epileptic human sclerotic hippocampal formation. We have focused our attention mainly on chandelier cells because, together with basket cells, they are considered to have powerful effects on spike generation. Chandelier cells represent a unique type of interneuron whose axon terminals (Ch-terminals) form synapses with the axon initial segments of cortical pyramidal cells and granular cells of the dentate gyrus. Different neurochemical subpopulations of chandelier cells have been identified by immunocytochemistry, mainly in the neocortex. Markers for Ch-terminals include the GABA transporter 1 (GAT-1), the polysialylated form of the cell-surface glycoprotein neural cell adhesion molecule (PSA-NCAM) and the calcium-binding proteins parvalbumin (PV) and calbindin D-28k (CB). In the normal hippocampal formation, GAT-1- and PV-immunoreactive (-ir) Ch-terminals were identified in the granular and polymorphic layers of the dentate gyrus, in the strata pyramidale and oriens of the CA fields, and in the pyramidal layer of the subicular complex. In addition, and in contrast to the hippocampus and dentate gyrus, subsets of Ch-terminals in the upper pyramidal layer of the normal subiculum express CB and PSA-NCAM. The sclerotic hippocampus of epileptic patients presented an impressive morphological and neurochemical reorganization of Ch-terminals and basket formations. This was apparent in the dentate gyrus and hippocampal formation, but not in the subiculum, which appeared to remain unaltered. Principally, numerous and more complex PV- and CB-ir Ch-terminals, as well as dense PV-ir basket formations, appeared in some hippocampal segments, whereas in other regions there was a lack of labelled elements. These changes varied considerably not only between different patients, but also within different hippocampal fields in a given patient. In general, the changes were not correlated with the clinical characteristics or degree of histopathological alterations observed in the patients, such as granular cell dispersion, neuron loss and proliferation of mossy fibres. However, some surviving neurons in the regions adjacent to the areas of neuron loss were consistently innervated by dense basket formations and complex Ch-terminals. These results indicate that, in the human epileptic hippocampus, GABAergic circuits are more highly modified than previously thought. When considered along with other extrahippocampal alterations, we suggest that these changes are important in the pathophysiology of temporal lobe epilepsy associated with hippocampal sclerosis.

Dendritic spines receive most excitatory inputs in the neocortex and are morphologically very diverse. Recent evidence has demonstrated linear relationships between the size and length of dendritic spines and important features of its synaptic junction and time constants for calcium compartmentalisation. Therefore, the morphologies of dendritic spines can be directly interpreted functionally. We sought to explore whether there were potential differences in spine morphologies between areas and species that could reflect potential functional differences. For this purpose, we reconstructed and measured thousands of dendritic spines from basal dendrites of layer III pyramidal neurons from mouse temporal and occipital cortex and from human temporal cortex. We find systematic differences in spine densities, spine head size and spine neck length among areas and species. Human spines are systematically larger and longer and exist at higher densities than those in mouse cortex. Also, mouse temporal spines are larger than mouse occipital spines. We do not encounter any correlations between the size of the spine head and its neck length. Our data suggests that the average synaptic input is modulated according to cortical area and differs among species. We discuss the implications of these findings for common algorithms of cortical processing.

Down syndrome (DS) is the most frequent genetic cause of mental retardation. Cognitive dysfunction in these patients is correlated with reduced dendritic branching and complexity, along with fewer spines of abnormal shape that characterize the cortical neuronal profile of DS. DS phenotypes are caused by the disruptive effect of specific trisomic genes. Here, we report that overexpression of dual-specificity tyrosine phosphorylation-regulated kinase 1A, DYRK1A, is sufficient to produce the dendritic alterations observed in DS patients. Engineered changes in Dyrk1A gene dosage in vivo strongly alter the postnatal dendritic arborization processes with a similar progression than in humans. In cultured mammalian cortical neurons, we determined a reduction of neurite outgrowth and synaptogenesis. The mechanism underlying neurite dysgenesia involves changes in the dynamic reorganization of the cytoskeleton.

One of the main challenges in neuroscience is to define the detailed structural design of the nervous system. This challenge is one of the first steps towards understanding how neural circuits contribute to the functional organization of the nervous system. In the cerebral cortex pyramidal neurons are key elements in brain function as they represent the most abundant cortical neuronal type and the main source of cortical excitatory synapses. Therefore, many researchers are interested in the analysis of the microanatomy of pyramidal cells since it constitutes an excellent tool for better understanding cortical processing of information. Computational models of neuronal networks based on real cortical circuits have become useful tools for studying certain aspects of the functional organization of the neocortex. Neuronal morphologies (morphological models) represent key features in these functional models. For these purposes, synthetic or virtual dendritic trees can be generated through a morphological model of a given neuronal type based on real morphometric parameters obtained from intracellularly-filled single neurons. This paper presents a new method to construct virtual dendrites by means of sampling a branching model that represents the dendritic morphology. This method has been contrasted using complete basal dendrites from 374 layer II/III pyramidal neurons of the mouse neocortex.

The neuronal nicotinic acetylcholine receptors (nAChRs) are allosteric membrane proteins involved in multiple cognitive processes, including attention, learning, and memory. The most abundant form of heterooligomeric nAChRs in the brain contains the β2- and α4- subunits and binds nicotinic agonists with high affinity. In the present study, we investigated in the mouse the consequences of the deletion of one of the nAChR components: the β2-subunit (β2-/-) on the microanatomy of cortical pyramidal cells. Using an intracellular injection method, complete basal dendritic arbors of 650 layer III pyramidal neurons were sampled from seven cortical fields, including primary sensory, motor, and associational areas, in both β2-/- and WT animals. We observed that the pyramidal cell phenotype shows significant quantitative differences among different cortical areas in mutant and WT mice. In WT mice, the density of dendritic spines was rather similar in all cortical fields, except in the prelimbic/infralimbic cortex, where it was significantly higher. In the absence of the β2-subunit, the most significant reduction in the density of spines took place in this high-order associational field. Our data suggest that the β2-subunit is involved in the dendritic morphogenesis of pyramidal neurons and, in particular, in the circuits that contribute to the high-order functional connectivity of the cerebral cortex.

Adenosine is a neuromodulator which acts through adenosine receptors regulating functions such as inhibition of glutamate release. Adenosine A(1) and A(2A) receptor activations most often regulate opposing actions. Primary rat cortical neurons and rat C6 cells, an astrocytic derived cell line, were exposed to 100muM l-glutamate, and cell viability and transduction pathways mediated by both A(1) and A(2A) receptors were analyzed. Glutamate-induced excitotoxic damage was found only in cortical neurons, with C6 cells preserved. In C6 cells, adenosine A(1) and A(2A) receptors were increased and decreased, respectively. Consequently, A(1)-mediated adenylyl cyclase inhibition and A(2A)-mediated adenylyl cyclase stimulation were, respectively, increased and decreased after glutamate exposure. In cortical neurons, glutamate treatment increased both A(1) and A(2A) receptors. Moreover, adenylyl cyclase responsiveness to A(1) or A(2A) receptor agonists was heightened in these cells, in which pharmacological activation of AC induced cell death. Finally, activation of A(1) receptor or blockade of A(2A) receptor during glutamate treatment partially prevented the glutamate-induced cell death detected in cultured cortical neurons. Results show that adenosine receptors are regulated by glutamate, and that this regulation is dependent on the cell type, suggesting that adenosine receptors might be promising targets in the therapy against excitotoxic cell death.

12 pages, 4 figures, 4 tables.-- PMID: 18657522 [PubMed].-- Printed version published Sep 16, 2008., Repeated administration of drugs of abuse is thought to induce a variety of persistent changes in both behavior and brain morphology, including modifications of neurons from the brain regions involved in addiction. We have studied the morphology of the basal dendritic arbor of cortical pyramidal neurons in addiction-resistant Fischer 344 strain rats that self-administered morphine. Pyramidal neurons in the prelimbic and motor cortex were intracellularly injected with Lucifer Yellow in fixed tissue and they were reconstructed in three dimensions using Neurolucida software. Morphine self-administration did not produce significant changes in the structure of the dendritic arbors or in the spine density of pyramidal neurons in either the prelimbic or motor cortex of F344 rats. Moreover, pyramidal cell morphology did not differ in these two cortical areas in saline self-administered animals. However, when the structure of these cortical pyramidal cells from Fischer 344 rats was compared with that previously reported in addiction-prone Lewis rats in the same cortical areas, significant morphological differences were found between both strains. Indeed, these differences were not only observed following morphine self-administration but also in saline self-administered control animals. We suggest that strain differences in the structure of pyramidal cells in certain cortical areas might represent an anatomical substrate for the distinct vulnerability to the reinforcing effects of morphine exhibited by Fischer 344 and Lewis rats in operant self-administration paradigms., Morphine sulphate was kindly provided by the “Dirección General de Estupefacientes” (Spain). This work was supported by the “Ministerio de Educación y Ciencia” (grants BFI 2003–02745, BFU2006–13395 and “Genómica y Proteómica” GEN2003–20651-C06–06 to J DeF) and by the “Fondo de Inversiones Sanitarias” FIS01–05–01; the “Plan Nacional sobre Drogas” PNSD2000–2003; the “Comunidad Autónoma de Madrid” CAM08.8/0010.1/2003, “Plan de Promoción de la Investigación en la UNED” and “Salud y Farmacia” SAF2007–64890 grants to EA. IB-Y is a “Juan de la Cierva” postdoctoral fellow of the Ministry of Science and Technology.

A fundamental and long-standing question in neuroscience is what is special about the neocortex of humans and how does it differ from that of other species. It is generally thought that during evolution, the neocortex expanded in larger brains due to the addition of microcircuits with the same basic structure. Hence, it is considered unlikely that new types of neurons or other fundamental differences exist. Here, we focus on certain features that have been highlighted by comparative microanatomical studies of the neocortex that emphasize the differences between the human neocortex and that of other mammals. The notion of uniformity in the neocortex with respect to the density and the types of neurons found in columns has been recently challenged. We present evidence that the uniformity of cortex has been overstated and that there are actually wide variations in cortical organization. The proportion of GABAergic interneurons is higher in primates than in rats and, moreover, certain subtypes of interneurons are lacking or greatly modified in some species. Together with the distinct synaptology in the neuropil and in the number of synapses per neuron, these differences clearly highlight the variability in the design of microcircuits between cortical areas and species. Given our ignorance regarding many aspects of the organization of the cerebral cortex and the great number of mammalian species whose cortical structure remains unexplored, what we currently conceive as general diagrams of basic neocortical circuits should be considered an oversimplification. Based on our studies and those of a number of other laboratories, we support the idea that the human neocortex shows unique specialization that is likely to be crucial for human cortical function.

The detailed microanatomical study of the human cerebral cortex began in 1899 with the experiments of Santiago Ramón y Cajal, who applied the Golgi method to define the structure of the visual, motor, auditory and olfactory cortex. In the first article of this series, he described a special type of interneuron in the visual cortex capable of exerting its influence in the vertical dimension. These neurons are now more commonly referred to as double-bouquet cells (DBCs). The DBCs are readily distinguished owing to their characteristic axons that give rise to tightly interwoven bundles of long, vertically oriented axonal collaterals resembling a horsetail (DBC horsetail). Nevertheless, the most striking characteristic of these neurons is that they are so numerous and regularly distributed that the DBC horsetails form a microcolumnar structure. In addition, DBCs establish hundreds of inhibitory synapses within a very narrow column of cortical tissue. These features have generated considerable interest in DBCs over recent years, principally among those researchers interested in the analysis of cortical circuits. In the present chapter, we shall discuss the morphology, synaptic connections and neurochemical features of DBCs that have been defined through the study of these cells in different cortical areas and species. We will mainly consider the immunocytochemical studies of DBCs that have been carried out in the visual cortex (areas 17 and 18) of human and macaque monkey. We will see that there are important differences in the morphology, number and distribution of DBC horsetails between areas 17 and 18 in the primate. This suggests important differences in the microcolumnar organization between these areas, the functional significance of which awaits detailed correlative physiological and microanatomical studies.

12 pages, 7 figures, 3 tables.-- PMID: 16195469 [PubMed].-- Available online Sep 29, 2005., Neocortical circuits share anatomical and physiological similarities among different species and cortical areas. Because of this, a ‘canonical’ cortical microcircuit could form the functional unit of the neocortex and perform the same basic computation on different types of inputs. However, variations in pyramidal cell structure between different primate cortical areas exist, indicating that different cortical areas could be built out of different neuronal cell types. In the present study, we have investigated the dendritic architecture of 90 layer II/III pyramidal neurons located in different cortical regions along a rostrocaudal axis in the mouse neocortex, using, for the first time, a blind multidimensional analysis of over 150 morphological variables, rather than evaluating along single morphological parameters. These cortical regions included the secondary motor cortex (M2), the secondary somatosensory cortex (S2), and the lateral secondary visual cortex and association temporal cortex (V2L/TeA). Confirming earlier primate studies, we find that basal dendritic morphologies are characteristically different between different cortical regions. In addition, we demonstrate that these differences are not related to the physical location of the neuron and cannot be easily explained assuming rostrocaudal gradients within the cortex. Our data suggest that each cortical region is built with specific neuronal components., R.B.-P. thanks the ‘Comunidad de Madrid’ (01/0782/2000) and I.B.-Y. the MEC (AP2001-0671) for support. J.D. is supported by the Spanish Ministry of Education and Science (BFI2003-02745) and the Comunidad de Madrid (08.5/0027/2001.1). R.Y. thanks the NEI (EY11787) and the John Merck Fund for support and the Cajal Institute for hosting him as a visiting professor.

The consumption of drugs of abuse provokes sensitization, the development of tolerance, dependency, and eventually addiction. It is thought that these events are partially a consequence of drug-induced alterations in the organization of neuronal circuits in specific areas of the brain. In the present study, we have used intracellular injections of lucifer yellow to examine the alterations that may occur in cortical pyramidal neurons of addiction-prone Lewis rats following 15 days of self-administration of morphine. Specifically, the effects of morphine on the structure, size and branching complexity of the basal dendrites, and spine density were determined in the basal dendritic arbors of layer III pyramidal neurons in both the prelimbic and motor cortex. We found that following morphine self-administration, there was a reduction in the size and branching complexity of the dendritic arbors of pyramidal cells in the motor cortex. In contrast, prelimbic pyramidal neurons from these morphine-treated animals had larger and longer basal dendritic arbors. Furthermore, the spine density on pyramidal neurons was higher in both cortical regions of morphine self-administered rats. These results suggest that at least part of the behavioral changes produced by repeated opiate administration may be attributed to alterations in pyramidal cell structure.

The detailed microanatomical study of the human cerebral cortex began in 1899 with the experiments of Santiago Ramon y Cajal, who applied the Golgi method to define the structure of the visual, motor, auditory and olfactory cortex. In the first article of this series, he described a special type of interneuron in the visual cortex capable of exerting its influence in the vertical dimension. These neurons are now more commonly referred to as double-bouquet cells (DBCs). The DBCs are readily distinguished owing to their characteristic axons that give rise to tightly interwoven bundles of long, vertically oriented axonal collaterals resembling a horsetail (DBC horsetail). Nevertheless, the most striking characteristic of these neurons is that they are so numerous and regularly distributed that the DBC horsetails form a microcolumnar structure. In addition, DBCs establish hundreds of inhibitory synapses within a very narrow column of cortical tissue. These features have generated considerable interest in DBCs over recent years, principally among those researchers interested in the analysis of cortical circuits. In the present chapter, we shall discuss the morphology, synaptic connections and neurochemical features of DBCs that have been defined through the study of these cells in different cortical areas and species. We will mainly consider the immunocytochemical studies of DBCs that have been carried out in the visual cortex (areas 17 and 18) of human and macaque monkey. We will see that there are important differences in the morphology, number and distribution of DBC horsetails between areas 17 and 18 in the primate. This suggests important differences in the microcolumnar organization between these areas, the functional significance of which awaits detailed correlative physiological and microanatomical studies.

7 pages, 4 figures, 1 table.-- PMID: 16457955 [PubMed]., Dendritic spines of pyramidal cells are the main postsynaptic targets of cortical excitatory synapses and as such, they are fundamental both in neuronal plasticity and for the integration of excitatory inputs to pyramidal neurons. There is significant variation in the number and density of dendritic spines among pyramidal cells located in different cortical areas and species, especially in primates. This variation is believed to contribute to functional differences reported among cortical areas. In this study, we analyzed the density of dendritic spines in the motor, somatosensory and visuo-temporal regions of the mouse cerebral cortex. Over 17,000 individual spines on the basal dendrites of layer III pyramidal neurons were drawn and their morphologies compared among these cortical regions. In contrast to previous observations in primates, there was no significant difference in the density of spines along the dendrites of neurons in the mouse. However, systematic differences in spine dimensions (spine head size and spine neck length) were detected, whereby the largest spines were found in the motor region, followed by those in the somatosensory region and those in visuo-temporal region., This work was supported by the Spanish Ministry of Education and Science (BFI2003-02745), the Comunidad de Madrid (grant 08.5/0027/2001), the National Health and Medical Research Council of Australia (G.N.E.) and the National Eye Institute and the Human Frontiers Science Project (R.Y.). I.B.-Y. is research fellowship of the Spanish Ministry of Education and Science (AP 2001-0671).

Double bouquet cells (DBCs) are neocortical gamma-aminobutyric acid (GABA)ergic interneurons characterized by the vertical bundling of its axon, which are generally termed "bundles" or "horse-tails." Using immunocytochemistry for the calcium binding protein calbindin, we have analyzed the morphology, density, and distribution of DBC horse-tails in different cortical areas of the human cortex (Brodmann's areas 10, 4, 3b, 22, 18, and 17). Although DBC horse-tails were very numerous and regularly distributed in all cortical areas, variations were observed both in terms of morphology and density. We distinguished two major classes of DBC horse-tails: the thicker complex type (type I) that had more axon collaterals; and the simple type (type II). The density of DBC horse-tails was significantly higher in areas 17, 18, 22, and 4 than in areas 3b and 10. Moreover, the proportion of type I and type II DBC horse-tails varied in the cortical areas studied. We also examined the distribution of DBC horse-tails in frontal, parietal, and occipital areas of different mammalian species. We found DBCs to be present in carnivores but not in rodents, lagomorphs, or artiodactyls. In carnivores, relatively few DBC horse-tails can be identified and they were generally found in the occipital cortex. Therefore, there is significant variability in the morphology and distribution of DBC horse-tails in different species and cortical areas. We conclude that, although these interneurons may be an important element in the organization of cortical microcolumns in primates, this is not the case in other mammalian species.

Since the discovery in the 1970s that dendritic abnormalities in cortical pyramidal neurons are the most consistent pathologic correlate of mental retardation, research has focused on how dendritic alterations are related to reduced intellectual ability. Due in part to obvious ethical problems and in part to the lack of fruitful methods to study neuronal circuitry in the human cortex, there is little data about the microanatomical contribution to mental retardation. The recent identification of the genetic bases of some mental retardation associated alterations, coupled with the technology to create transgenic animal models and the introduction of powerful sophisticated tools in the field of microanatomy, has led to a growth in the studies of the alterations of pyramidal cell morphology in these disorders. Studies of individuals with Down syndrome, the most frequent genetic disorder leading to mental retardation, allow the analysis of the relationships between cognition, genotype and brain microanatomy. In Down syndrome the crucial question is to define the mechanisms by which an excess of normal gene products, in interaction with the environment, directs and constrains neural maturation, and how this abnormal development translates into cognition and behaviour. In the present article we discuss mainly Down syndrome-associated dendritic abnormalities and plasticity and the role of animal models in these studies. We believe that through the further development of such approaches, the study of the microanatomical substrates of mental retardation will contribute significantly to our understanding of the mechanisms underlying human brain disorders associated with mental retardation. © 2004 Elsevier Ltd. All rights reserved.

Dendritic spines receive most excitatory inputs in the neocortex and are morphologically very diverse. Recent evidence has demonstrated linear relationships between the size and length of dendritic spines and important features of its synaptic junction and time constants for calcium compartmentalisation. Therefore, the morphologies of dendritic spines can be directly interpreted functionally. We sought to explore whether there were potential differences in spine morphologies between areas and species that could reflect potential functional differences. For this purpose, we reconstructed and measured thousands of dendritic spines from basal dendrites of layer III pyramidal neurons from mouse temporal and occipital cortex and from human temporal cortex. We find systematic differences in spine densities, spine head size and spine neck length among areas and species. Human spines are systematically larger and longer and exist at higher densities than those in mouse cortex. Also, mouse temporal spines are larger than mouse occipital spines. We do not encounter any correlations between the size of the spine head and its neck length. Our data suggests that the average synaptic input is modulated according to cortical area and differs among species. We discuss the implications of these findings for common algorithms of cortical processing.