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Changes in sphingolipid metabolism regulate and/or alter many cellular functions in the brain. Ceramide, a central molecule of sphingolipid metabolism, is phosphorylated to ceramide-1-phosphate (C1P) by ceramide kinase (CerK). CerK and C1P were reported to regulate many cellular responses, but their roles in immune-related diseases in vivo have not been well elucidated. Thus, we investigated the effects of CerK knockout on the onset/progression of multiple sclerosis (MS), which is a chronic neurodegenerative disease accompanied by the loss of myelin sheaths in the brain. MS-model mice were prepared using a diet containing the copper chelator cuprizone (CPZ). Treatment of 8-week-old mice with 0.2% CPZ for 8 weeks resulted in motor dysfunction based on the Rota-rod test, and caused the loss of myelin-related proteins (MRPs) in the brain and demyelination in the corpus callosum without affecting synaptophysin levels. CerK knockout, which did not affect developmental changes in MRPs, ameliorated the motor dysfunction, loss of MRPs, and demyelination in the brain in CPZ-treated mice. Loss of tail tonus, another marker of motor dysfunction, was detected at 1 week without demyelination after CPZ treatment in a CerK knockout-independent manner. CPZ-induced loss of tail tonus progressed, specifically in female mice, to 6-8 weeks, and the loss was ameliorated by CerK knockout. Activities of ceramide metabolic enzymes including CerK in the lysates of the brain were not affected by CPZ treatment. Inhibition of CerK as a candidate for MS treatment was discussed., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Oral administration of bovine collagen peptide (CP) combined with calcium citrate (CC) has been found to inhibit bone loss in ovariectomized rats. However, the protective effects of CP and CP-CC against bone loss have not been investigated in a tail-suspension simulated microgravity (SMG) rat model. Adult Sprague-Dawley rats ( n = 40) were randomly divided into five groups ( n = 8): a control group with normal gravity, a SMG control group, and three SMG groups that underwent once-daily gastric gavage with CP (750 mg/kg body weight), CC (75 mg/kg body weight) or CP-CC (750 and 75 mg/kg body weight, respectively) for 28 days. After sacrifice, the femurs were analyzed by dual-energy X-ray absorptiometry, three-point bending mechanical tests, microcomputed tomography, and serum bone metabolic markers. Neither CP nor CP-CC treatment significantly inhibited bone loss in SMG rats, as assessed by dual-energy X-ray absorptiometry and three-point bending mechanical tests. However, both CP and CP-CC treatment were associated with partial prevention of the hind limb unloading-induced deterioration of bone microarchitecture, as demonstrated by improvements in trabecular number and trabecular separation. CP-CC treatment increased serum osteocalcin levels. Dietary supplementation with CP or CP-CC may represent an adjunct strategy to reduce the risk of fracture in astronauts., Competing Interests: The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.

Hypothermia is a condition in which the body's core temperature drops below 35.0 °C. Hypothermia is the opposite of hyperthermia, which the metabolism and body functions are abnormal. Severe hypothermia is a life-threatening problem that may cause atrial and ventricular dysrhythmias, coagulopathy, cardiac, and central nervous system depression. What is worse, it is fatal when untreated or treated improperly. Accidental deaths due to hypothermia resulting from immersion in cold water, especially involving naval fighters and maritime victims have occurred continually in the past years. Currently, the treatment of hypothermia has become a research focus. Rewarming is the only approach that should be considered for hypothermia treatment. However, the treatment is of low efficiency, and few active rewarming cases have been reported. It is well known that timely reperfusion is the best way to save the lives of patients with ischemia. Similarly, reoxygenation is effective for hypoxia. However, several studies have identified that improper reperfusion of ischemic tissues and reoxygenation of hypoxic tissues give rise to further injury. Analogically, this study attempts to propose the hypothesis that hypothermia-rewarming injury may also exist. When suffered from hypothermia, both the blood circulation and the oxygen supply in the body will be affected in a deficient state, an injury may also appear in the improper rewarming process. In a word, hypothermia-rewarming may be a double-edged sword., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Detection of developmental neurotoxicity (DNT) has been recognized as a major challenge by regulatory bodies and science. In search of sensitive and specific test methods, spontaneous tail coiling of embryonic zebrafish has been recommended as a promising tool for identification of DNT-inducing chemicals. The present study was designed to develop a protocol for a prolonged test to study neurotoxicity during the entire development of coiling movement in zebrafish embryos. Ambient illumination was found to modulate coiling activity from the very onset of tail movements representing the earliest behavioral response to light possible in zebrafish. In the dark, embryos displayed increased coiling activity in a way known from photokinesis, a stereotypical element of the visual motor response. Elevated coiling activity during dark phases allows for the development of test strategies that integrate later coiling movements under the control of a further developed nervous system. Furthermore, zebrafish embryos were exposed to ethanol, and coiling activity was analyzed according to the new test protocol. Exposure of embryos to non-teratogenic concentrations of ethanol (0.4-1%) resulted in a delay of the onset of coiling activity and heartbeat. Moreover, ethanol produced a dose-dependent increase in coiling frequency at 26 h post-fertilization, indicating the involvement of neurotoxic mechanisms. Analysis of coiling activity during prolonged exposure allowed for (1) attributing effects on coiling activity to different mechanisms and (2) preventing false interpretation of results. Further research is needed to verify the potential of this test protocol to distinguish between different mechanisms of neurotoxicity., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Infrared thermography has been suggested as a non-invasive, objective tool to evaluate animal welfare. In this study, we investigated: 1) how body temperature, measured through thermal imaging, is affected by different mild stressors frequently experienced by laboratory mice; 2) which methodology to use for assessing temperature variations with infrared thermography; 3) whether the chosen stressors cause anxiety in mice. Eighty C57BL/6 male mice were included in the study. The mice were allocated to either a control group or one of three groups being subjected to a mild stressor once daily for 4 days: 1) anaesthesia with isoflurane for 10 min; 2) handling by scruffing; 3) intraperitoneal injection of 0.2 ml 0.9% saline. On all four intervention days, thermal images were obtained in all groups and all animals were assessed for fur status and body weight. On day five, all animals were tested in the elevated-plus-maze for 5 min. From the thermal images, the maximum eye temperature, the maximum tail base temperature and the average body temperature were obtained. Ten minutes of anaesthesia with isoflurane led to a decrease in maximum eye temperature, average body temperature and maximum tail base temperature. The animals recovered from this drop in temperature within 10 min. No drop in temperature was seen after scruffing or intraperitoneal injection of saline. Based on the number of missing values, intra-rater and inter-rater agreement, the average body temperature was found most ideal for measuring body temperature variations in mice. Finally, the elevated plus maze did not reveal any differences in anxiety between the groups and the body weight did not decrease at any time point during the study., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Urodele amphibians have a tremendous capacity for the regeneration of appendages, including limb and tail, following injury. While studies have focused on the cellular and morphological changes during appendicular regeneration, the signaling mechanisms that govern these cytoarchitectural changes during the regenerative response are unclear. In this study, we describe the essential role of hedgehog (Hh) and Wnt signaling pathways following tail amputation in the newt. Quantitative PCR studies revealed that members of both the Hh and Wnt signaling pathways, including the following: shh, ihh, ptc-1, wnt-3a, β-catenin, axin2, frizzled (frzd)-1, and frzd-2 transcripts, were induced following injury. Continuous pharmacological-mediated inhibition of Hh signaling resulted in spike-like regenerates with no evidence of tissue patterning, whereas activation of Hh signaling enhanced the regenerative process. Pharmacological-mediated temporal inhibition experiments demonstrated that the Hh-mediated patterning of the regenerating tail occurs early during regeneration and Hh signals are continuously required for proliferation of the blastemal progenitors. BrdU incorporation and PCNA immunohistochemical studies demonstrated that Hh signaling regulates the cellular proliferation of the blastemal cells following amputation. Similarly, Wnt inhibition resulted in perturbed regeneration, whereas its activation promoted tail regeneration. Using an inhibitor-activator strategy, we demonstrated that the Wnt pathway is likely to be upstream of the Hh pathway and together these signaling pathways function in a coordinated manner to facilitate tail regeneration. Mechanistically, the Wnt signaling pathway activated the Hh signaling pathway that included ihh and ptc-1 during the tail regenerative process. Collectively, our results demonstrate the absolute requirement of signaling pathways that are essential in the regulation of tail regeneration.

Systemic or central administration of 2-deoxy-d-glucose (2DG), a competitive inhibitor of glucose utilization, induces hypothermia in awake animals and humans. This response is mediated by the central nervous system, though the neural mechanism involved is largely unknown. In this study, I examined possible involvement of the forebrain, which contains the hypothalamic thermoregulatory center, and the medullary rostral raphe/parapyramidal regions (rRPa/PPy), which mediate hypoxia-induced heat-loss responses, in 2DG-induced hypothermia in urethane-chloralose-anesthetized, neuromuscularly blocked, artificially ventilated rats. The intravenous injection of 2DG (250mgkg(-1)) elicited an increase in tail skin temperature and decreases in body core temperature and the respiratory exchange ratio, though it did not induce any significant change in the metabolic rate. These results indicate that the hypothermic response was caused by an increase in heat loss, but not by a decrease in heat production and that it was accompanied by a decrease in carbohydrate utilization and/or an increase in lipid utilization as energy substrates. Complete surgical transection of the brainstem between the hypothalamus and the midbrain had no effect on the 2DG-induced hypothermic responses, suggesting that the hindbrain, but not the forebrain, was sufficient for the responses. However, pretreatment of the rRPa/PPy with the GABAA receptor blocker bicuculline methiodide, but not with vehicle saline, greatly attenuated the 2DG-induced responses, suggesting that the 2DG-induced hypothermia was mediated, at least in part, by GABAergic neurons in the hindbrain and activation of GABAA receptors on cutaneous sympathetic premotor neurons in the rRPa/PPy., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Introduction: The rat tail exhibits functional impairment after cauda equina injury. Our goal was to better understand the innervation and roles of muscles that control the tail., Methods: Adult rats received either: (1) ventral root injury; (2) caudales nerve injury; or (3) mapping of sacrococcygeal myotomes. Activation of small muscles within the tail itself (intrinsics) was compared with that of larger lumbosacral muscles acting on the tail (extrinsics). Behavioral testing of tail movement was done 1 week later., Results: Rats that received ventral root injury exhibited multiple behavioral deficits, whereas rats with injury to caudales nerves maintained more fully preserved tail movement. Mapping studies revealed much broader overlap of myotomes for extrinsic muscles., Conclusions: Extrinsic tail muscles play a greater role in tail movement in the rat than their intrinsic counterparts and are innervated by multiple neurological segments. These findings have major implications for future research on cauda equina injury., (© 2014 Wiley Periodicals, Inc.)

Endocannabinoids (ECBs) such as anandamide (AEA) act by activating cannabinoid type 1 (CB1) or 2 (CB2) receptors. The anxiolytic effect of drugs that facilitate ECB effects is associated with increase in AEA levels in several encephalic areas, including the prefrontal cortex (PFC). Activation of CB1 receptors by CB1 agonists injected directly into these areas is usually anxiolytic. However, depending on the encephalic region being investigated and on the stressful experiences, opposite effects were observed, as reported in the ventral HIP. In addition, contradictory results have been reported after CB1 activation in the dorsal HIP (dHIP). Therefore, in the present paper we have attempted to verify if directly interfering with ECB metabolism/reuptake in the prelimbic (PL) portion of the medial PFC (MPFC) and dHIP would produce different effects in two conceptually distinct animal models: the elevated plus maze (EPM) and the Vogel conflict test (VCT). We observed that drugs which interfere with ECB reuptake/metabolism in both the PL and in the dentate gyrus of the dHIP induced anxiolytic-like effect, in both the EPM and in the VCT via CB1 receptors, suggesting that CB1 signaling in these brain regions modulates defensive responses to both innate and learned threatening stimuli. This data further strengthens previous results indicating modulation of hippocampal and MPFC activity via CB1 by ECBs, which could be therapeutically targeted to treat anxiety disorders., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Ocimum suave willd is one of the plants traditionally used for the treatment of inflammation and related disorders in different parts of Ethiopia. The aim of the current study was to evaluate the analgesic and antipyretic activities of the solvent fractions (n-butanol and water) of O. suave aqueous leaves extract., Materials and Methods: Acetic acid writhing and tail flick tests were used to evaluate the analgesic activity, and yeast-induced fever in mice was used to evaluate the antipyretic activity of the solvent fractions., Results: Both solvent fractions exhibited inhibitory effect against acetic acid induced writhing at all tested dose levels in a dose dependent manner. The water fraction inhibited writhing by 47.69% at a dose of 200 mg/kg which was comparable to that by ASA, the standard drug. In the tail flick test, 200 mg/kg dose of both solvent fractions showed significant activity (P<0.05) after 0.5h, 1h and 3hrs of their administration. Both n- butanol and water fractions produced significant reduction in yeast induced fever at all doses employed., Conclusion: From these findings, it can be concluded that the n-butanol and water fractions of O. suave aqueous leaves extract have potential analgesic and antipyretic activity in mice.

Neuromodulators, such as serotonin (5-hydroxytryptamine, 5-HT) and noradrenalin, play an essential role in regulating the motor and sensory functions in the spinal cord. We have previously shown that in the rat spinal cord the activity of aromatic L-amino acid decarboxylase (AADC) cells to produce 5-HT from its precursor (5-hydroxytryptophan, 5-HTP) is dramatically increased following complete spinal cord transection. In this study, we investigated whether a partial loss of 5-HT innervation could similarly increase AADC activity. Adult rats with spinal cord hemisected at thoracic level (T11/T12) were used with a postoperation interval at 5 days or 60 days. Using immunohistochemistry, first, we observed a significant reduction in the density of 5-HT-immunoreactive fibers in the spinal cord below the lesion on the injured side for both groups. Second, we found that the AADC cells were similarly expressed on both injured and uninjured sides in both groups. Third, increased production of 5-HT in AADC cells following 5-HTP was seen in 5-day but not in 60-day postinjury group. These results suggest that plastic changes of the 5-HT system might happen primarily in the subchronic phase and for longer period its function could be compensated by plastic changes of other intrinsic and/or supraspinal modulation systems.

This study investigated the intrinsic connections of a key-structure of the endogenous pain inhibitory system, the pedunculopontine tegmental nucleus (PPTN), in post-ictal antinociceptive process through synaptic inactivation of the PPTN with cobalt chloride. Male Wistar rats (n = 6 or 7 per group), weighing 250-280 g, had the tail-flick baseline recorded and were submitted to a stereotaxic surgery for the introduction of a guide-cannula aiming at the PPTN. After 5 days of postoperative recovery, cobalt chloride (1 mM/0.2 µL) or physiological saline (0.2 µL) were microinjected into the PPTN and after 5 min, the tail-withdrawal latency was measured again at 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, and 120 min after seizures evoked by intraperitoneal injection of pentylenetetrazole (64 mg/kg). The synaptic inactivation of PPTN decreased the post-ictal antinociceptive phenomenon, suggesting the involvement of PPTN intrinsic connections in the modulation of pain, during tonic-clonic seizures. These results showed that the PPTN may be crucially involved in the neural network that organizes the post-ictal analgesia., (© 2014 Wiley Periodicals, Inc.)

Introduction: Antidepressant drugs are used in the treatment of pain as an adjuvant or alone. It has been shown that antidepressant drugs have analgesic effects in various diseases (diabetic neuropathy, low back pain, cancer pain etc.) Sertraline is a potent serotonin re-uptake inhibitor. Some antidepressant drugs inhibited both of the reuptake of serotonin and of noradrenaline. These drugs are called serotonin-noradrenaline re-uptake inhibitors (SNRIs). Milnacipran is a serotonin-noradrenaline re-uptake inhibitor. We have studied the analgesic effects of sertraline and milnacipran after acute and chronic application in tail-flick test in mice., Methods: The analgesic effects of milnacipran (10, 30, 50 mg/kg) and sertraline (10, 20, 50 mg/kg) were measured after acute and chronic application in tail flick test. The analgesic effects of milnacipran (30 mg/kg) or sertraline (50 mg/kg) were evaluated after the application of L-NAME (10 mg/kg), naloxone (5 mg/kg), prazosin (1 mg/kg), ondansetron (0.1 mg/kg) in tail flick test., Results: Milnacipran (30 mg/kg) and sertraline (50 mg/kg) produced statistically significant analgesic effect compared to their control values after acute and chronic application in tail-flick test. The analgesic effects of both milnacipran (30 mg/kg) and sertraline (50 mg/kg) in the presence of L-NAME (10 mg/kg), naloxone (5 mg/kg), ondansetron (0.1 mg/kg) and prazosin (1 mg/kg) were inhibited in tail-flick test., Conclusion: These results indicate that the analgesic effects of milnacipran and sertraline are related to nitrergic, opioidergic, serotonergic and adrenergic system (Fig. 8, Ref. 23).

A critical feature of tendons and ligaments is their ability to resist rupture when overloaded, resulting in strains or sprains instead of ruptures. To treat these injuries more effectively, it is necessary to understand how overload affects the primary load-bearing elements of these tissues: collagen fibrils. We have investigated how repeated subrupture overload alters the collagen of tendons at the nanoscale. Using scanning electron microscopy to examine fibril morphology and hydrothermal isometric tension testing to look at molecular stability, we demonstrated that tendon collagen undergoes a progressive cascade of discrete plasticity damage when repeatedly overloaded. With successive overload cycles, fibrils develop an increasing number of kinks along their length. These kinks-discrete zones of plastic deformation known to contain denatured collagen molecules-are accompanied by a progressive and eventual total loss of D-banding along the surface of fibrils, indicating a loss of native molecular packing and further molecular denaturation. Thermal analysis of molecular stability showed that the destabilization of collagen molecules within fibrils is strongly related to the amount of strain energy dissipated by the tendon after yielding during tensile overload. These novel findings raise new questions about load transmission within tendons and their fibrils and about the interplay between crosslinking, strain-energy dissipation ability, and molecular denaturation within these structures., (Copyright © 2012 Orthopaedic Research Society.)

Lymphangiogenic cytokines such as vascular endothelial growth factor-C (VEGF-C) are critically required for lymphatic regeneration; however, in some circumstances, lymphatic function is impaired despite normal or elevated levels of these cytokines. The recent identification of anti-lymphangiogenic molecules such as interferon-γ (IFN-γ), transforming growth factor-β1, and endostatin has led us to hypothesize that impaired lymphatic function may represent a dysregulated balance in the expression of pro/anti-lymphangiogenic stimuli. We observed that nude mice have significantly improved lymphatic function compared with wild-type mice in a tail model of lymphedema. We show that gradients of lymphatic fluid stasis regulate the expression of lymphangiogenic cytokines (VEGF-A, VEGF-C, and hepatocyte growth factor) and that paradoxically the expression of these molecules is increased in wild-type mice. More importantly, we show that as a consequence of T-cell-mediated inflammation, these same gradients also regulate expression patterns of anti-lymphangiogenic molecules corresponding temporally and spatially with impaired lymphatic function in wild-type mice. We show that neutralization of IFN-γ significantly increases inflammatory lymph node lymphangiogenesis independently of changes in VEGF-A or VEGF-C expression, suggesting that alterations in the balance of pro- and anti-lymphangiogenic cytokine expression can regulate lymphatic vessel formation. In conclusion, we show that gradients of lymphatic fluid stasis regulate not only the expression of pro-lymphangiogenic cytokines but also potent suppressors of lymphangiogenesis as a consequence of T-cell inflammation and that modulation of the balance between these stimuli can regulate lymphatic function.

It is known that mechanical loading leads to an increase in bone mass through a positive shift in the balance between bone formation and bone resorption. How the remodeling sites change over time as an effect of loading remains, however, to be clarified. The purpose of this paper was to investigate how bone formation and resorption sites are modulated by mechanical loading over time by using a new imaging technique that extracts three dimensional formation and resorption parameters from time-lapsed in vivo micro-computed tomography images. To induce load adaptation, the sixth caudal vertebra of C57BL/6 mice was cyclically loaded through pins in the adjacent vertebrae at either 8 N or 0 N (control) three times a week for 5 min (3000 cycles) over a total of 4 weeks. The results showed that mechanical loading significantly increased trabecular bone volume fraction by 20% (p<0.001) and cortical area fraction by 6% (p<0.001). The bone formation rate was on average 23% greater (p<0.001) and the bone resorption rate was on average 25% smaller (p<0.001) for the 8 N group than for the 0 N group. The increase in bone formation rate for the 8 N group was mostly an effect of a significantly increased surface of bone formation sites (on average 16%, p<0.001), while the thickness of bone formation packages was less affected (on average 5% greater, p<0.05). At the same time the surface of bone resorption sites was significantly reduced (on average 15%, p<0.001), while the depth of resorption pits remained the same. For the 8 N group, the strength of the whole bone increased significantly by 24% (p<0.001) over the loading period, while the strain energy density in the trabecular bone decreased significantly by 24% (p<0.001). In conclusion, mouse tail vertebrae adapt to mechanical loading by increasing the surface of formation sites and decreasing the surface of resorption sites, leading to an overall increase in bone strength. This new imaging technique will provide opportunities to investigate in vivo bone remodeling in the context of disease and treatment options, with the added value that both bone formation and bone resorption parameters can be nondestructively calculated over time., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Unlabelled: We evaluated the effectiveness of intrathecal antagonists of α1- (WB4101) and α2- (idazoxan) adrenoceptors and serotonergic (methysergide), opioid (naloxone), muscarinic (atropine), GABA(A) (bicuculline) and GABA(B) (phaclofen) receptors in blocking 2- or 100-Hz electroacupuncture (EA)-induced analgesia (EAIA) in the rat tail-flick test. EA was applied bilaterally to the Zusanli and Sanyinjiao acupoints in lightly anesthetized rats. EA increased tail-flick latency, where the effect of 2-Hz EA lasted longer than that produced by 100-Hz EA. The 2-Hz EAIA was inhibited by naloxone or atropine, was less intense and shorter after WB4101 or idazoxan, and was shorter after methysergide, bicuculline, or phaclofen. The 100-Hz EAIA was less intense and shorter after naloxone and atropine, less intense and longer after phaclofen, shorter after methysergide or bicuculline, and remained unchanged after WB4101 or idazoxan. We postulate that the intensity of the effect of 2-Hz EA depends on noradrenergic descending mechanisms and involves spinal opioid and muscarinic mechanisms, whereas the duration of the effect depends on both noradrenergic and serotonergic descending mechanisms, and involves spinal GABAergic modulation. In contrast, the intensity of 100-Hz EAIA involves spinal muscarinic, opioid, and GABA(B) mechanisms, while the duration of the effects depends on spinal serotonergic, muscarinic, opioid, and GABA(A) mechanisms., Perspective: The results of this study indicate that 2- and 100-Hz EA induce analgesia in the rat tail-flick test activating different descending mechanisms at the spinal cord level that control the intensity and duration of the effect. The adequate pharmacological manipulation of such mechanisms may improve EA effectiveness for pain management., (Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.)

Following spinal cord injury (SCI) neurons caudal to the injury are capable of rhythmic locomotor-related activity that can form the basis for substantial functional recovery of stepping despite the loss of crucial brain stem-derived neuromodulators like serotonin (5-HT). Here we investigated the contribution of constitutive 5-HT(2) receptor activity (activity in the absence of 5-HT) to locomotion after SCI. We used a staggered hemisection injury model in rats to study this because these rats showed a robust recovery of locomotor function and yet a loss of most descending axons. Immunolabeling for 5-HT showed little remaining 5-HT below the injury, and locomotor ability was not correlated with the amount of residual 5-HT. Furthermore, blocking 5-HT(2) receptors with an intrathecal (IT) application of the neutral antagonist SB242084 did not affect locomotion (locomotor score and kinematics were unaffected), further indicating that residual 5-HT below the injury did not contribute to generation of locomotion. As a positive control, we found that the same application of SB242084 completely antagonized the muscle activity induced by exogenous application of the 5-HT(2) receptor agonists alpha-methyl-5-HT (IT). In contrast, blocking constitutive 5-HT(2) receptor activity with the potent inverse agonist SB206553 (IT) severely impaired stepping as assessed with kinematic recordings, eliminating most hindlimb weight support and overall reducing the locomotor score in both hind legs. However, even in the most severely impaired animals, rhythmic sweeping movements of the hindlimb feet were still visible during forelimb locomotion, suggesting that SB206553 did not completely eliminate locomotor drive to the motoneurons or motoneuron excitability. The same application of SB206553 had no affect on stepping in normal rats. Thus while normal rats can compensate for loss of 5-HT(2) receptor activity, after severe spinal cord injury rats require constitutive activity in these 5-HT(2) receptors to produce locomotion.

Study Design: An in vivo rat-tail model was adopted to study the structural changes of degenerated intervertebral disc after different traction protocols., Objective: To investigate the effects of traction with different modes and magnitudes on disc with simulated degeneration., Summary of Background Data: Traction has been commonly used in clinical practice for treating low back pain. Its effects on disc with degeneration have not been fully investigated., Methods: Forty-seven mature rats were used. Continuous static compression of 11 N was applied to the rat caudal 8-9 disc for 2 weeks to simulate disc degeneration. Tractions with different modes (static or intermittent) and magnitudes (1.4 N or 4.2 N) were applied to the degenerated disc for 3 weeks. The disc height was quantified in vivo on days 4, 18, and 39. The treated discs were then harvested for morphologic analysis., Results: Significant decrease in disc height with degenerative morphologic changes was observed after the application of the static compression. The changes in disc height after the application of traction were found to be magnitude dependent. Continuous decrease in disc height was observed after 4.2-N traction, whereas the disc height maintained after traction of 1.4 N. However, no obvious morphologic change was found in comparison with the degenerated discs without traction., Conclusion: Although traction was not demonstrated to have restored disc with degeneration, traction with relatively low magnitude was found to have significant beneficial effect in maintaining disc height of degenerated disc, and it might be a potential intervention to slow down the process of degeneration. Future studies of the effects of low-magnitude traction on degenerated disc are recommended.

Background and Purpose: The burden of intracerebral hemorrhage associated with oral anticoagulants (OAC-ICH) is growing. However, little is known about the pathophysiology of W-ICH. Herein, we refine a mouse model of OAC-ICH using repetitive T2* MRI to describe kinetics of hematoma enlargement, and establish a benchside point of care INR assay (PoC) for assessment of anticoagulation., Methods: C57/BL6 mice drank warfarin (0.4mg/kg/24h) in their water. ICH was induced by stereotactic injection of collagenase type VII (0.045U) into the left striatum. Hemorrhagic blood volume was quantified by MRI T2* images and on cryosections 48h after ICH induction. Kinetics of hematoma expansion were compared in strongly, moderately, and non-anticoagulated mice using repeated MRI T2* imaging. The PoC INR technique was validated against standard laboratory INR, and tail vein bleeding time (TVBT)., Results: PoC INR correlated with central laboratory measurements (r=0.989; p<0.0001) and with TVBT (r=0.982; p<0.0001). Hematoma volume was 21.2+/-6.7mm(3) in heavily (PoC INR 4-5), 12.3+/-4.8 in moderately (INR 2-3), and 8.6+/-3.3 in non-anticoagulated mice (INR<1.2). Hematoma volume determined from cryosections and T2* MRI correlated well (r=0.922). Strength of anticoagulation was associated with neurologic outcome. Hematoma enlargement occurred mainly during the first 3h in anticoagulated mice., Conclusions: PoC allows repeated benchside INR measurements in individual mice which reflect the level of anticoagulation. Stronger anticoagulation results in larger hematoma volumes. As hematoma enlargement occurs mainly during the first hours, potential hemostatic therapies should be tested early in this OAC-ICH model., (Copyright 2010 Elsevier B.V. All rights reserved.)

Peripheral afferent denervation induces reorganization of somatotopic maps in the primary somatosensory cortex (S1). In the present study, we investigated somatotopic map plasticity after tail cut. Neonatal mice at postnatal days (P) 2-3 and adult mice at eight weeks of age were anesthetized with ether, and approximately two thirds of the tail was cut from the tip. Both groups of mice were anesthetized with urethane (1.7g/kg, i.p.) at 10weeks of age, and transcranial flavoprotein fluorescence imaging was performed in the S1. Neural activities in the S1 were elicited by vibratory stimulation applied to the contralateral hindpaw or the tail in control mice. The cortical areas activated by hindpaw, tail base, and tail tip stimuli were placed in this order according to the medial and posterior direction. In mice with tail cut, the tail base area moved to the more medial and posterior area corresponding to the tail tip in control mice. The shift of the tail base area was observed in both neonatal and adult tail cut mice, indicating the absence of a critical period before eight weeks. Medial and posterior shift of the tail base area with regard to the bregma was confirmed in tail cut mice. These data suggest that transcranial flavoprotein fluorescence imaging is a useful technique for investigating somatosensory map plasticity in mice., (Copyright 2010 Elsevier B.V. All rights reserved.)

It has been proven that norepinephrine (NE) regulates antinociception through its action on alpha-adrenoceptors located in brain nuclei, spinal cord, and peripheral organs. However, the supraspinal mechanism of noradrenergic pain modulation is controversial. The present study was aimed at investigating the nociceptive effects induced by injecting different doses of NE and phentolamine into the caudate putamen (CPU) of rats. The thermal pain threshold of the rats was measured by performing a tail-flick test. The tail-flick latency (TFL) was measured at 2-60 min after microinjection of the drugs. Our results revealed that the thermal pain threshold increased (long TFL) after the administration of a low dose of NE (2 microg/2 microl) and decreased (short TFL) after injection of a high dose of NE (8 microg/2 microl). In contrast, the pain threshold decreased after the administration of a low dose of phentolamine (1 microg/2 microl), while it increased after injection of a high dose of phentolamine (4 microg/2 microl). These results indicated that the injection of different doses of NE in the CPU of the rats produced opposite effects on the pain threshold, as determined by the tail-flick tests., ((c) 2010 Elsevier Ireland Ltd. All rights reserved.)

Accurate measurement of perfusion with dynamic contrast enhanced CT requires an arterial input curve (AIC) uncontaminated by venous sources. Arterio-venous anastomoses (AVAs) are sources of contamination if contrast is injected intravenously. We seek to identify AVAs in mice and associated errors in perfusion measurements. Six transgenic mice with spontaneous prostate tumor were scanned with a micro-CT scanner (GE Healthcare (GE)) using a high resolution anatomical and a lower resolution perfusion protocol. For the anatomical protocol, a CT scan was performed during injection of an iodinated contrast agent (Hypaque) into a tail vein. Images covering the thoracic, abdominal and pelvic regions at an isotropic resolution of 175 microm were reconstructed and rendered in 3D to show the arterial and venous tree (Advantage Window, GE). For the perfusion protocol, each mouse was continuously scanned for 40 s and the contrast agent (Hypaque) was injected via a tail vein 5 s into scanning. Tumor images were reconstructed every second. Tumor blood flow (BF) and volume (BV) maps were calculated with CT perfusion software (GE) using AIC measured either from abdominal aorta (AA) or tail (caudal) artery (TA). In all mice, there was an AVA from the bifurcation of the inferior vena cava to the tail artery shunting venous blood and portion of the contrast agent injected into the tail vein into the TA. Contrast arrival time at the TA preceded that at the AA by 3.3 +/- 0.5 s (P < 0.05). Mean tumor BV and BF values calculated with AA versus TA were 10.0 +/- 1.8 versus 4.8 +/- 2.1 ml (100 g)(-1) (P < 0.05) and 108.8 +/- 26.5 versus 33.0 +/- 8.5 ml min(-1) 100 g(-1) (P < 0.05), respectively. AVA in the murine pelvic region can result in inaccurate and more variable measurements of pelvic organ/tissue perfusion when the tail artery is used as the AIC.

In contrast to mammals, adult teleost fish exhibit a vast potential for central nervous system regeneration after injury. Among other mechanisms, this capacity is mediated by replacement of cells lost to injury by new neurons and glia. Here, we examined the spatio-temporal dynamics of apoptosis, and its relationship to the generation and the differentiation of new cells, during this cell replacement phase. As an experimental paradigm, caudal transection of the spinal cord in the teleost fish Apteronotus leptorhynchus was used. During the cell replacement phase, there was a rather constant percentage of new cells (identified by incorporation of 5-bromo-2'-deoxyuridine into newly synthesized DNA) that underwent apoptosis (identified by anti-active caspase-3 immunolabeling). Many of these cells were also immunopositive for the marker proteins Hu C/D or glial fibrillary acidic protein, indicating that a large portion of cells undergo apoptosis after differentiation into neurons or glia, respectively. The spatial distribution of apoptotic cells was uneven, displaying a radial peak in the mid parenchymal regions and a longitudinal peak at the site of the initial spinal transection. The latter persisted for over 100 days post-injury, indicating possible problems in the integration of new cells at the interface between the old, intact tissue and the regenerated portion of the spinal cord. Taken together, the results of the present study are consistent with the hypothesis that apoptosis plays a role in the development of the new tissue during the cell replacement phase of the regenerating teleostean spinal cord.

Cauda equina injuries may produce severe leg and pelvic floor dysfunction, for which no effective treatments exist. We are developing a rat cauda equina injury model to allow nerve root identification and surgical repair. One possible difficulty in implementing any repair strategy after trauma in humans involves the correct identification of proximal and distal ends of nerve roots separated by the injury. Two series of studies were carried out. In Series 1, we electrically stimulated segmental contributors to the dorsal and ventral caudales nerves in order to characterize the recruitment patterns of muscles controlling rat tail movements. In Series 2, we attempted to identify individual nerve roots forming the cauda equina by both level of origin and function (i.e., dorsal or ventral), based solely upon the recruitment patterns in response to electrical stimulation. For Series 1 studies, electrical stimulation of the segmental contributors showed that all nerve roots-from the sixth lumbar to the first coccygeal-contributed to recruitment of muscles found at the base of the tail. Intrinsic tail muscles lying more distally in the tail showed a more root-specific pattern of innervation. For Series 2, the rate of successful identification of an unknown nerve root as being ventral was very high (>95%), and only somewhat lower (approximately 80%) for dorsal roots. Correctly identifying the level of origin of that root was more difficult, but for ventral roots this rate still exceeded 90%. Using the rat cauda equina model, we have shown that stimulus-evoked EMG can be used to identify ventral nerve roots innervating tail muscles with a high degree of accuracy. These findings support the feasibility of using this conceptual approach for identifying and repairing damaged human cauda equina nerve roots based on stimulus-evoked recruitment of muscles in the leg and pelvic floor.

Prolonged hand-transmitted vibration exposure in the workplace has been recognized for almost a century to cause neurodegenerative and vasospastic disease. Persistence of the diseased state for years after cessation of tool use is of grave concern. To understand persistence of vibration injury, the present study examined recovery of nerve conduction velocity and structural damage of myelinated axons in a rat tail vibration model. Both 7 and 14 days of vibration (4 h/day) decreased conduction velocity. The decrease correlated directly with the increased percentage of disrupted myelinated axons. The total number of myelinated axons was unchanged. During 2 months of recovery, conduction velocity returned to control level after 7-day vibration but remained decreased after 14-day vibration. The rat tail model provides insight into understanding the persistence of neural deficits in hand-arm vibration syndrome.

Background: The nucleus raphe magnus (NRM) is involved in thermoregulatory processing. There is a correlation between changes in the firing rates of the cells in the NRM and the application of the peripheral thermal stimulus., Introduction: we examined the effect of reversible inactivation and excitation of NRM on mechanisms involved in tail blood flow (TBF) regulation in hypothermia., Methods: Hypothermia was induced in Male Wistar rats and cannula was implanted above the NRM. To evaluate the effect of nucleus inactivation on TBF, the amount of TBF was measured by Laser Doppler in hypothermic rats, before and after lidocaine microinjection into NRM. TBF was also measured after glutamate microinjection to assess the effect of nucleus excitation in hypothermic rats., Results: Results indicated that after dropping TBF by hypothermia, microinjection of lidocaine into NRM significantly decreased TBF from 54.43 +- 5.7 to 46.81 +- 3.4, whereas glutamate microinjection caused a significant increase from 44.194 +- 0.6 to 98 +- 10.0 CONCLUSION: These data suggest that NRM have thermoregulatory effect in response to hypothermia.

Electroacupuncture (EA) has long been used as conservative treatment for low back pain (LBP). Its effect on relief of back pain has been demonstrated in many clinical studies. However, whether it has any effect on the biological properties of an intervertebral disc, which is one of the major causes of LBP, is still unclear. The aim of this study was, therefore, to investigate the effects of EA with different simulation frequencies on an intervertebral disc with simulated degeneration using an in-vivo rat-tail model. In this study, 33 rats were used. Disc degeneration was simulated in the rat caudal 8-9 disc via continuous static compressive loading of 11 N for 2 weeks. EA with a frequency of 2 or 100 Hz was then applied to the degenerated disc for 3 weeks with 3 sessions/week and 20 min/session. The intervertebral disc height was measured before and after compression as well as after EA intervention for 3 weeks. The static compression was found to result in a reduction in the disc height of about 22 per cent. There was no evidence that this change could be reversed after resting or the EA intervention. However, EA at 100 Hz was found to induce a further decrease in disc height, which was not shown for the rats after resting or EA at 2 Hz. The results of this study showed that effects of EA on disc degeneration are frequency dependent and adverse effects could result if EA at a certain frequency was used.

We have previously demonstrated that (+)-morphine and (-)-morphine pretreated spinally for 45 min stereoselectively attenuates the tail-flick inhibition produced by (-)-morphine given spinally in the mouse. The present study is then undertaken to determine if the same phenomenon observed in the mouse spinal cord can also take place in the ventral periaqueductal gray of the rat. Pretreatment with (+)-morphine for 45 min at 0.3 to 3.3 fmol dose-dependently attenuated the tail-flick inhibition produced by (-)-morphine (9 nmol) given into the ventral periaqueductal gray. Likewise, pretreatment with (-)-morphine for 45 min at a higher dose (3-900 pmol), which given alone did not affect the baseline tail-flick latency, also dose-dependently attenuated the tail-flick inhibition produced by (-)-morphine. Thus, (+)-morphine is approximately 270,000-fold more potent than (-)-morphine in attenuating the (-)-morphine-produced tail-flick inhibition. The attenuation of the (-)-morphine-produced tail-flick inhibition induced by (+)-morphine or (-)-morphine was dose-dependently reversed by (+)-naloxone (27.5 to 110 pmol) pretreatment for 50 min given into the ventral periaqueductal gray. Pretreatment with the sigma receptor antagonist BD1047 (N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(dimethylamino)ethylamine dihydrobromide) (11-45 nmol) for 45 min given into the ventral periaqueductal gray also reversed dose-dependently the attenuation of the (-)-morphine-produced tail-flick inhibition induced by (+)-morphine or (-)-morphine, indicating that the effects are mediated by the activation of the sigma receptors. Since (+)-morphine, (-)-morphine and (+)-naloxone do not have any affinity for the naloxone-inaccessible sigma receptors, we therefore propose that (+)-morphine and (-)-morphine attenuate the (-)-morphine-produced tail-flick inhibition via the activation of the naloxone-sensitive sigma receptor originally proposed by Tsao and Su [Tsao, L.T., Su, T.P., 1997. Naloxone-sensitive, haloperidol-sensitive, [(3)H](+)-SKF-1047-binding protein partially purified from rat liver and rat brain membranes: an opioid/sigma receptor. Synapse 25, 117-124].

Background: As previously shown, Paraquat (PQ) treatments of Xenopus developing embryos mainly induce a characteristic developmental alteration we named "abnormal tail flexure." PQ oxidative activity has been indicated as the cause of this malformation. Since PQ evokes reactive oxygen species (ROS), among which hydroxyl radicals (OH(*)), and H(2)O(2) can be converted to (OH(*)) via Fenton reaction, we compared here the lethal and teratogenic potentials of both oxidants by using the Frog Embryo Teratogenesis Assay-Xenopus (FETAX), in order to grasp eventual similarities in their teratogenic activity., Methods: Xenopus embryos were exposed, from stage 8 to stage 47, at 368, 491, 612, and 735 microM H(2)O(2) and 0.388 microM PQ. The probit analysis of H(2)O(2) mortality and malformed larva percents gave a 598.82 microM Lethal Concentration 50% (LC(50)) and 536.04 microM Teratogenic Concentration 50% (TC(50)) from which a 1.11 Teratogenic Index (T.I.) has been calculated. This T.I. value should allow the classification of H(2)O(2) as a non-teratogenic compound., Results: A comparison of H(2)O(2) mortality and malformed larva percents with those obtained from PQ exposure showed the higher embryotoxicity of PQ, but, markedly, both compounds mainly induced the "abnormal tail flexure." Histological analysis of both H(2)O(2) and PQ malformed embryo tails showed a similar distorted morphology of both somites and myocytes. Some of muscle cells were necrotic and affected by an apical enlargement as well as a detachment from the connective tissue of intersomitic boundaries., Conclusions: In our opinion, both of the tested chemicals likely weaken the mechanical bridge connecting the myocyte contractile apparatus to the extracellular matrix, therefore causing the detachment of some of tail myocytes from their connectival septum as well as their apical enlargement. This could lead to the unbalance of tail tensional forces and, in turn, to the appearance of the "abnormal tail flexure."

Purpose: Antineoplastic drugs, such as cisplatin (CDDP), are severely neurotoxic, causing disabling peripheral neuropathies with clinical signs known as chemotherapy-induced peripheral neurotoxicity. Cotreatment with neuroprotective agents and CDDP has been proposed for preventing or reversing the neuropathy. Erythropoietin given systemically has a wide range of neuroprotective actions in animal models of central and peripheral nervous system damage. However, the erythropoietic action is a potential cause of side effects if erythropoietin is used for neuroprotection. We have successfully identified derivatives of erythropoietin, including carbamylated erythropoietin, which do not raise the hematocrit but retain the neuroprotective action exerted by erythropoietin., Experimental Design: We have developed previously an experimental chemotherapy-induced peripheral neurotoxicity that closely resembles CDDP neurotoxicity in humans. The present study compared the effects of erythropoietin and carbamylated erythropoietin (50 microg/kg/d thrice weekly) on CDDP (2 mg/kg/d i.p. twice weekly for 4 weeks) neurotoxicity in vivo., Results: CDDP given to Wistar rats significantly lowered their growth rate (P < 0.05), with slower sensory nerve conduction velocity (P < 0.001) and reduced intraepidermal nerve fibers density (P < 0.001 versus controls). Coadministration of CDDP and erythropoietin or carbamylated erythropoietin partially but significantly prevented the sensory nerve conduction velocity reduction. Both molecules preserved intraepidermal nerve fiber density, thus confirming their neuroprotective effect at the pathologic level. The protective effects were not associated with any difference in platinum concentration in dorsal root ganglia, sciatic nerve, or kidney specimens., Conclusions: These results widen the spectrum of possible use of erythropoietin and carbamylated erythropoietin as neuroprotectant drugs, strongly supporting their effectiveness.

Paralyzed skeletal muscle sometimes becomes faster and more fatigable after spinal cord injury (SCI) because of reduced activity. However, in some cases, pronounced muscle activity in the form of spasticity (hyperreflexia and hypertonus) occurs after long-term SCI. We hypothesized that this spastic activity may be associated with a reversal back to a slower, less fatigable muscle. In adult rats, a sacral (S2) spinal cord transection was performed, affecting only tail musculature and resulting in chronic tail spasticity beginning 2 wk later and lasting indefinitely. At 8 mo after injury, we examined the contractile properties of the segmental tail muscle in anesthetized spastic rats and in age-matched normal rats. The segmental tail muscle has only a few motor units (<12), which were easily detected with graded nerve stimulation, revealing two clear motor unit twitch durations. The dominant faster unit twitches peaked at 15 ms and ended within 50 ms, whereas the slower unit twitches only peaked at 30-50 ms. With chronic injury, this slow twitch component increased, resulting in a large overall increase (>150%) in the fraction of the peak muscle twitch force remaining at 50 ms. With injury, the peak muscle twitch (evoked with supramaximal stimulation) also increased in its time to peak (+48.9%) and half-rise time (+150.0%), and decreased in its maximum rise (-35.0%) and decay rates (-40.1%). Likewise, after a tetanic stimulation, the tetanus half-fall time increased by 53.8%. Therefore the slow portion of the muscle was enhanced in spastic muscles. Consistent with slowing, posttetanic potentiation was 9.2% lower and the stimulation frequency required to produce half-maximal tetanus decreased 39.0% in chronic spinals. Interestingly, in spastic muscles compared with normal, whole muscle twitch force was 81.1% higher, whereas tetanic force production was 38.1% lower. Hence the twitch-to-tetanus ratio increased 104.0%. Inconsistent with overall slowing, whole spastic muscles were 61.5% more fatigable than normal muscles. Thus contrary to the classical slow-to-fast conversion that is seen after SCI without spasticity, SCI with spasticity is associated with a mixed effect, including a preservation/enhancement of slow properties, but a loss of fatigue resistance.

Ketorolac tromethamine has to be given every 6 hr intramuscularly in patients for acute pain, so to avoid frequent dosing and patient inconvenience we found it to be a suitable candidate for parenteral controlled delivery by biodegradable microspheres for the present study. Ketorolac tromethamine-loaded microspheres were prepared by o/w emulsion solvent evaporation technique using different polymers: polycaprolactone, poly lactic-co-glycolic acid (PLGA 65/35), and poly lactic-co-glycolic acid (PLGA 85/15). To tailor the release profile of drug for several days, blends of PLGA 65/35 and PLGA 85/15 were prepared with polycaprolactone (PCL) in different ratios. The results revealed that microspheres made with 1:3 (PLGA65/35:PCL) blend released 97% of the drug in 5 days as compared 97% in 30 days in with pure PLGA65/35 microspheres. Microspheres made with 1:1 (PLGA65/35:PCL) and 3:1 (PLGA65/35:PCL released 98% of the drug in 30 days. In microspheres made with 1:3 (PLGA85/15:PCL), almost the entire drug was released in a week whereas in batches made with pure PLGA85/15 and 3:1 (PLGA 85/15:PCL) more than 80% of the drug was released in 60 days as compared with 96% in 60 days in 1:1 (PLGA85/15:PCL). Higher encapsulation efficiency was obtained with microspheres made with pure PLGA 65/35. These formulations were characterized for particle size analysis by Malvern mastersizer that revealed particle size in range of 12-15 micron and 12-22 micron for microspheres made with polymer blends of PLGA 65/35:PCL and PLGA85/15:PCL, respectively. In pure PLGA65/35 and PLGA85/15, particle size was 28 micron and 8 micron, respectively. Surface topography was studied by scanning electron microscopy that revealed a spherical shape of microspheres. From our study it as concluded that with careful selection of different polymers and their combinations, we can tailor the release of ketorolac tromethamine for long periods.

I and coauthor previously reported the memory facilitation effect of morphine. The main purpose of this study was to evaluate the involvement of the N-methyl-D-aspartate (NMDA) receptor in associative tolerance to morphine by a contextual procedure. Antinociceptive response latency was measured by the tail-pinch method during repeated morphine (5 mg/kg, s.c.) injection for four consecutive days with pretreatment by dizocilpine (0.01, 0.05, 0.1 mg/kg, i.p.) at 30 min prior to morphine injection in the training phase and before and after morphine injection in the test phase. The nociceptive response latency was shortened by the single administration of dizocilpine (0.05 to 0.25 mg/kg, i.p.). Pretreatment by dizocilpine at 0.05 or 0.1 mg/kg weakened the antinociception to morphine on Day 1, but decreased the tolerance throughout the training phase. In the test phase, the animals were allocated into the same and different contexts. In the test phase, hyperalgesia before morphine injection in the same context and antinociception after morphine injection in the different context were evident in the saline-pretreated group in the training phase, but they were not observed in those contexts in the dizocilpine-pretreated groups. These results suggest that memory dysfunction with dizocilpine inhibits the recovery of associative tolerance to morphine by contextual change.

Here we report the characterization of a mouse model of the Bernard-Soulier syndrome generated by a targeted disruption of the gene encoding the glycoprotein (GP) Ibbeta subunit of the GP Ib-IX complex. Similar to a Bernard-Soulier model generated by disruption of the mouse GP Ibalpha subunit, GP Ibbeta(Null) mice display macrothrombocytopenia and a severe bleeding phenotype. When examined by transmission electron microscopy, the large platelets produced by a GP Ibbeta(Null) genotype revealed alpha-granules with increased size as compared with the alpha-granules from control mouse platelets. Data are presented linking the overexpression of a septin protein, SEPT5, to the presence of larger alpha-granules in the GP Ibbeta(Null) platelet. The SEPT5 gene resides approximately 250 nucleotides 5' to the GP Ibbeta gene and has been associated with modulating exocytosis from neurons and platelets as part of a presynaptic protein complex. Fusion mRNA transcripts present in megakaryocytes can contain both the SEPT5 and GP Ibbeta coding sequences as a result in an imperfect polyadenylation signal within the 3' end of both the human and mouse SEPT5 genes. We observed a 2- to 3-fold increase in SEPT5 protein levels in platelets from GP Ibbeta(Null) mice. These results implicate SEPT5 levels in the maintenance of normal alpha-granule size and may explain the variant granules associated with human GP Ibbeta mutations and the Bernard-Soulier syndrome.

1. This study examined whether different parts of the rat anterior pretectal nucleus (APtN) may be involved in the spinal control of brief (tail flick test) or persistent (surgical incision of the plantar aspect of a hind paw) noxious inputs via activation of descending pathways. 2. We have confirmed that stimulation of the dorsal APtN produces a strong antinociceptive effect in the tail flick test, as opposed to a very weak effect obtained from the ventral APtN. Stimulation at the ventral APtN was the most effective part of the nucleus against a persistent incisional pain. 3. The incisional pain was significantly increased following injection of 1 or 2% lignocaine (0.25 microL) into the nucleus, but the effect was more intense after neural block of the ventral rather than the dorsal APtN. Injection of 2% lignocaine (0.10 microL) into the ventral, but not dorsal, APtN significantly increased the perception of the incisional pain. 4. We conclude that the effect of stimulating the APtN depends on the site of stimulation and model of pain used. Sustained noxious stimuli activate pathways from the ventral APtN to reduce further noxious spinal inputs. The noxious stimulation produced during the tail flick test may be not enough to activate the same circuitry, but electrical stimulation at the dorsal APtN is very effective in inhibiting brief thermal noxious inputs at the spinal level.

Hot flushes are one of the most frequent symptoms in menopausal women. We investigated effect of soybean isoflavones (Soyaflavone HG) on nifedipine-induced flushing in ovariectomized mice. Ovariectomy markedly aggravated nifedipine-induced increase in tail skin temperature. Soyaflavone HG (10 mg/kg, p.o., once a day for 5 days) inhibited nifedipine-induced flushing in ovariectomized mice. The inhibitory effect of Soyaflavone HG was significantly reversed by an estrogen-receptor antagonist, ICI 182,780, suggesting that Soyaflavone HG prevents nifedipine-induced flushing partially through estrogen receptors. We presented the experimental evidence suggesting that soybean isoflavones including Soyaflavone HG have the benefits for menopausal hot flushes.

The nematode Caenorhabditis elegans is proving to be an attractive model organism for investigating innate immune responses to infection. Among the known pathogens of C. elegans is the bacterium Microbacterium nematophilum, which adheres to the nematode rectum and postanal cuticle, inducing swelling of the underlying hypodermal tissue and causing mild constipation. We find that on infection by M. nematophilum, an extracellular signal-regulated kinase (ERK) mitogen-activated protein (MAP) kinase cascade mediates tail swelling and protects C. elegans from severe constipation, which would otherwise arrest development and cause sterility. Involvement in pathogen defense represents a new role for ERK MAP kinase signaling in this organism.

We assessed (1) the time courses of cold and mechanical allodynia in both hindpaws and the tail, and (2) the relationship of the allodynia signs between different sites following spinal cord hemisection. Under enflurane anesthesia, rats were subjected to spinal hemisection at T13. The hemisected rats exhibited a significant increase in mechanical and cold allodynia signs of both hindpaws and the tail for 22-26 weeks postoperatively. In addition, mechanical allodynia signs were significantly correlated not only between the ipsilateral and the contralateral hindpaws, but also between the hindpaws and the tail. These results suggested that cold and mechanical allodynia developed extensively and lasted for a long time following spinal cord hemisection, and mechanical allodynia shown at different sites may be induced at least in part by common generating mechanisms.

The present study was designed to examine the effects of diazepam, nitrazepam, desipramine and haloperidol on tail-swing behavior in mice and to characterize the effects of diazepam. Mice were suspended with rubber bands tied around their upper bodies in order to force their heads upwards. The duration of tail-swing behavior was then measured. Diazepam (0.3 and 1 mg/kg) and nitrazepam (0.3 and 1 mg/kg) significantly depressed tail-swing behavior, while they did not affect ambulation or muscle tone. In contrast, desipramine (10-30 mg/kg) did not affect tail-swing behavior, but at doses of 17.5 and 30 mg/kg produced a marked reduction in ambulation. Haloperidol (0.15 mg/kg) significantly decreased both tail-swing behavior and ambulation. The benzodiazepine receptor antagonist flumazenil (1 and 10 mg/kg), the benzodiazepine receptor inverse agonist beta-carboline-3-carboxylic acid N-methylamide (beta-CCM; 3 mg/kg) and the GABA(A) receptor antagonist bicuculline (3 mg/kg) reversed the effects of diazepam (1 mg/kg) on tail-swing behavior, although administered alone they failed to influence such behavior. These results suggest that anxiety and/or fear are responsible for tail-swing behavior., ((c) 2003 Prous Science. All rights reserved.)

Neuropeptide FF, one of the mammalian PQRFamides, has been reported to affect the latency of the tail-flick response in rat. We intended to examine the nociceptive effect by the peptide PQRFamides from the comparative aspect. Using the dot immunoblot method with antiserum to FMRFamide as an assay system, a peptide (frog's nociception-related peptide, fNRP) which has the C-terminal sequence PQRFamide was isolated from the brain of the frog, Rana catesbeiana. The determined sequence, SIPNLPQRF-NH(2), is the same as that named first (frog growth hormone-releasing peptide-gene-related peptide-1: fGRP-RP-1, which is encoded in the cDNA of the fGRP precursor. Since the peptide was isolated from the frog brain, we tested another amphibian, the newt, which has a tail, by the hot beam tail-flick test. Intraperitoneal injection of fNRP significantly increased the latency of the pain response (tail-flick) 90 min after administration. The effect was blocked by simultaneous administration of 5 mM naloxone. The result provides evidence for the interaction of fNRP and opioid steps in the analgesia pathways in the newt.

It has been reported that systemic injection of arginine vasopressin (AVP) induces a drop in body core temperature (T(c)), but little is known about the mechanisms involved. Because glutamate is an important excitatory neurotransmitter involved in a number of thermoregulatory actions, in the present study, we tested the hypothesis that glutamate plays a role in systemic AVP-induced hypothermia. Wistar rats were pretreated intracerebroventricularly (icv) with kynurenic acid, an antagonist of l-glutamate ionotropic receptors, alpha-methyl-(4-carboxyphenyl)glycine (MCPG), an antagonist of l-glutamate metabotropic receptors, or saline 15 min before intravenous injection of AVP (2 microg/kg) or saline. T(c), brown adipose tissue (BAT) temperature, blood pressure, heart rate, and tail skin temperature were measured continuously. Administration of saline icv followed by intravenous AVP caused a significant drop in T(c) brought about by a reduction in BAT thermogenesis and an increase in heat loss through the tail. MCPG treatment (icv) did not affect the fall in T(c) induced by AVP. Treatment with kynurenic acid (icv) abolished AVP-induced hypothermia but did not affect the AVP-evoked rise in blood pressure or drop in heart rate and BAT temperature. Heat loss through the tail was significantly reduced in animals injected with AVP and pretrated with kynurenic acid. These data indicate that ionotropic receptors of l-glutamate in the central nervous system participate in peripheral AVP-induced hypothermia by affecting heat loss through the tail.

To investigate the involvement of nuclear factor kappa B1 (NF-kappaB1; p50/p105) in electroacupuncture (EA)-induced analgesia, 2 and 100 Hz EA stimulations were applied at acupoint ST36 (Zusanli) in NF-kappaB1 knockout mice. EA was performed for 30 min and tail-flick latencies (TFLs) were evaluated every 15 min for 1 h. Wild-type mice displayed a 63.3% increase in TFLs compared to baseline after 2 Hz EA, whereas NF-kappaB1+/- mice exhibited a 41.8% increase and NF-kappaB1-/- mice showed only a 3.9% increase of TFLs. The TFLs of 100 Hz EA showed similar trends: a 72.6% increase of TFLs in wild-type, a 38.6% increase in NF-kappaB1+/- and a 9.3% increase in NF-kappaB1-/- mice. The present findings suggest that NF-kappaB1 may play a crucial role in both low and high frequency EA-induced analgesic effects.

Lateral hypothalamus (LHA) plays a very important role in the modulation of nociceptive behaviour. The stimulation of LHA is known to produce analgesia of both tonic and phasic pain. The present study reports hyperalgesia induced by lateral hypothalamic lesions and the effect of fetal (gestation day 16) hypothalamic transplant on the nociceptive response to phasic thermal noxious stimulation [tail flick latency (TFL)] in LHA lesioned rats. The TFL decreased significantly (12.91 +/- 3.91 sec to 10.51+/- 1.23 sec) following LHA lesion. However, after transplantation, the TFL did not change. This is the first report of a hypothalamic transplant inducing recovery of a nociceptive response.

We investigated whether conscious rats exhibit hyperalgesia to noxious mechanical stimuli during tail reperfusion following transient tail ischaemia. Mechanical stimuli were delivered by three mechanical algometers, differing in contact area, geometry and rate of application. Tail ischaemia was induced by applying a pneumatic tourniquet to the base of the tail until the rats exhibited escape behaviour. Control animals had a sham tourniquet placed on their tails. During tail reperfusion, there was significant hyperalgesia when the noxious mechanical stimulus was applied by a narrow bar transverse to the tail, less when applied by a rubber piston, and there was no hyperalgesia when the stimulus was punctate, similar to a von Frey hair. Repeated application of the mechanical stimuli themselves, at 30-min intervals, did not induce hyperalgesia. Rats subjected repetitively to the combination of the bar algometer and tail ischaemia at intervals of at least 48 h, for a total period of three weeks, exhibited progressively enhanced hyperalgesia to the bar algometer, and also enhanced hyperalgesia to noxious ischaemic and thermal stimuli. Rats therefore do exhibit hyperalgesia to mechanical stimuli following conditioning ischaemia, but the nature of the hyperalgesia depends critically on the geometry of the algometer, and the time course of the hyperalgesia was different to that which manifests to a noxious thermal stimulus.

This study was designed to determine the magnitude and duration of the analgesic effect of three commonly used opioids: buprenorphine (0.5 mg/kg for rats; 2.0 mg/kg for mice), butorphanol (2.0 mg/kg for rats; 5.0 mg/kg for mice), and morphine (10 mg/kg for rats and mice). We used two standard tests, the hot plate and tail flick assays, to measure opioid analgesia in 62 male, 200 to 300 g Sprague-Dawley rats and 61 male, 25 to 35 g ICR mice. We obtained five baseline measurements then administered the drugs subcutaneously. Morphine gave the highest analgesic effect and was intermediate in duration (2 to 3 h in rats and mice) of analgesia. Butorphanol provided the lowest level of and shortest (1 to 2 h in rats and mice) analgesia. Buprenorphine had an intermediate analgesic effect and the longest duration (6 to 8 h in rats and 3 to 5 h in mice). In light of our results, we recommend the use of morphine (with frequent redosing) for severe pain, butorphanol for mild pain of short duration, and buprenorphine for mild to moderate pain of increased duration. The dosing intervals suggested by our study are 2 to 3 h for morphine in both rats and mice, 1 to 2 h for butorphanol in both rats and mice; and 6 to 8 h in rats and 3 to 5 h in mice for buprenorphine.

CB1 cannabinoid receptors are widely distributed in the central nervous system where they mediate most of the cannabinoid-induced responses. Here we have evaluated the interactions between the CB1 cannabinoid receptors and the endogenous opioid system by assaying a number of well-characterized opioid responses, e.g. antinociception and stress-mediated effects, on mutant mice in which the CB1 receptor gene was invalidated. The spontaneous responses to various nociceptive stimuli (thermal, mechanical and visceral pain) were not changed in mutant CB1 mice. Furthermore, the absence of the CB1 cannabinoid receptor did not modify the antinociceptive effects induced by different opioid agonists: morphine (preferential mu opioid agonist), D-Pen2-D-Pen5-enkephalin (DPDPE) and deltorphin II (selective delta opioid agonists), and U-50,488H (selective kappa opioid agonist) in the hot-plate and tail-immersion tests. In contrast, the stress-induced opioid mediated responses were modified in CB1 mutants. Indeed, these mutants did not exhibit antinociception following a forced swim in water at 34 degrees C and presented a decrease in the immobility induced by the previous exposure to electric footshock. However, the antinociception induced by a forced swim in water at 10 degrees C was preserved in CB1 mutants. These results indicate that CB1 receptors are not involved in the antinociceptive responses to exogenous opioids, but that a physiological interaction between the opioid and cannabinoid systems is necessary to allow the development of opioid-mediated responses to stress.

Two classes of neurons with distinct responses to opioids have been identified in the rostral ventromedial medulla (RVM), a region with a well-documented role in nociceptive modulation. 'Off-cells' are activated, indirectly, by opioids, and are likely to exert a net inhibitory effect on nociceptive processing. 'On-cells' are directly inhibited by opioids, and there is evidence that these neurons can, under various conditions, facilitate nociception. We showed previously that excitatory amino acid (EAA) neurotransmission is crucial to the nocifensor reflex-related on-cell burst, but plays little role in maintaining the ongoing activity of off-cells. The aim of the present study was to determine whether EAA transmission contributes to the activation of off-cells and the concomitant behavioral antinociception that follow systemic opioid administration. The non-selective EAA receptor antagonist kynurenate was infused into the RVM (1 nmol/200 nl) of lightly anesthetized rats prior to administration of morphine (1.5 mg/kg i.v). Off-cell, on-cell and neutral cell firing, as well as, tail flick response (TF) latencies were recorded. Kynurenate, significantly attenuated the characteristic opioid activation of off-cells. As a group, off-cells in kynurenate-treated animals did not become continuously active, and continued to exhibit tail-flick related pauses in firing. On-cell and neutral cell responses to opioid administration were unchanged. Opioid inhibition of the TF was also reduced, although baseline TF latency was unaffected, by RVM kynurenate. EAA-mediated activation of off-cells, thus has an important role in opioid analgesia. The present observations underscore the importance of excitatory interactions among opioid-sensitive nociceptive modulatory circuits for systemic morphine analgesia, suggesting that such interactions are a critical factor in the synergistic relationships which have been demonstrated among these sites.