Abstract: Neurotoxicity induced by glutamate and other excitatory amino acids has been implicated in various neurodegenerative disorders including hypoxic ischemic events, trauma, and Alzheimer’s and Parkinson’s diseases. We examined the roles of nicotinic acetylcholine receptors (nAChRs) in survival of CNS neurons during excitotoxic events. Nicotine as well as other nicotinic receptor agonists protected cortical neurons against glutamate neurotoxicity via α4 and α7 nAChRs at least partly by inhibiting the process of apoptosis in near-pure neuronal cultures obtained from the cerebral cortex of fetal rats. Donepezil, galanatamine and tacrine, therapeutic acetylcholinesterase (AChE) inhibitors currently being used for treatment of Alzheimer’s disease also protected neuronal cells from glutamate neurotoxicity. Protective effects of nicotine and the AChE inhibitors were antagonized by nAChR antagonists. Moreover, nicotine and those AChE inhibitors induced up-regulation of nAChRs. Inhibitors for a non-receptor-type tyrosine kinase, Fyn, and janus-activated kinase 2, suppressed the neuroprotective effect of donepezil and galantamine. Furthermore, a phosphatidylinositol 3-kinase (PI3K) inhibitor also suppressed the neuroprotective effect of the AChE inhibitors. The phosphorylation of Akt, an effector of PI3K, and the expression level of Bcl-2, an anti-apoptotic protein, increased with donepezil and galantamine treatments. These results suggest that nicotine as well as AChE inhibitors, donepezil and galantamine, prevent glutamate neurotoxicity through α4 and α7 nAChRs and the PI3K-Akt pathway.

Abstract: This article summarizes some of the effects of stimulating muscarinic receptors on nerve cell activity as observed by recording from single nerve cells and cholinergic synapses in the peripheral and central nervous sytems It addresses the nature of the muscarinic receptor(s) involved and the ion channels and subcellular mechanisms responsible for the effects The article concentrates on three effects: postsynaptic excitation, postsynaptic inhibition, and presynaptic (auto) inhibition Postsynaptic excitation results primarily from the inhibition of potassium currents by M1/M3/M5 receptors, consequent upon activation of phospholipase C by the G protein Gq Postsynaptic inhibition results from M2-activation of inward rectifier potassium channels, consequent upon activation of Gi Presynaptic inhibition results from M2 or M4 inhibition of voltage-gated calcium channels, consequent upon activation of Go The segregation receptors, G proteins and ion channels, and the corelease of acetylcholine and glutamate from cholinergic fibres in the brain are also discussed

Abstract: Anxiety disorders are frequently long-lasting and debilitating for more than 40 million American adults. Although stressor exposure plays an important role in the etiology of some anxiety disorders, the mechanisms by which exposure to stressful stimuli alters central circuits that mediate anxiety-like emotional behavior are still unknown. Substantial evidence has implicated regions of the central extended amygdala, including the bed nucleus of the stria terminalis (BNST) and the central nucleus of the amygdala as critical structures mediating fear- and anxiety-like behavior in both humans and animals. These areas organize coordinated fear- and anxiety-like behavioral responses as well as peripheral stress responding to threats via direct and indirect projections to the paraventricular nucleus of the hypothalamus and brainstem regions (Walker et al. Eur J Pharmacol 463:199-216, 2003, Prog Neuropsychopharmacol Biol Psychiatry 33(8):1291-1308, 2009; Ulrich-Lai and Herman Nat Rev Neurosci 10:397-409, 2009). In particular, the BNST has been argued to mediate these central and peripheral responses when the perceived threat is of long duration (Waddell et al. Behav Neurosci 120:324-336, 2006) and/or when the anxiety-like response is sustained (Walker and Davis Brain Struct Funct 213:29-42, 2008); hence, the BNST may mediate pathological anxiety-like states that result from exposure to chronic stress. Indeed, chronic stress paradigms result in enhanced BNST neuroplasticity that has been associated with pathological anxiety-like states (Vyas et al. Brain Res 965:290-294, 2003; Pego et al. Eur J Neurosci 27:1503-1516, 2008). Here we review evidence that suggests that pituitary adenylate cyclase-activating polypeptide (PACAP) and corticotropin-releasing hormone (CRH) work together to modulate BNST function and increase anxiety-like behavior. Moreover, we have shown that BNST PACAP as well as its cognate PAC1 receptor is substantially upregulated following chronic stress, particularly in the BNST oval nucleus where PACAP-containing neurons closely interact with CRH-containing neurons (Kozicz et al. Brain Res 767:109-119, 1997; Hammack et al. Psychoneuroendocrinology 34:833-843, 2009). We describe how interactions between PACAP and CRH in the BNST may mediate stress-associated behaviors, including anorexia and anxiety-like behavior. These studies have the potential to define specific mechanisms underlying anxiety disorders, and may provide important therapeutic strategies for stress and anxiety management.

Abstract: Oxidative stress plays an important role in many neurodegenerative disorders. In this study, the effect of baicalein, a natural flavonoid isolated from the root of Scutellaria baicalensis G., on hydrogen peroxide (H2O2)-induced cytotoxicity in PC12 cells were investigated. Exposure of PC12 cells to 0.15 mM H2O2 for 20 min induced a significant decrease in cell viability accompanied by increased oxidative stress, mitochondrial dysfunction, downregulation of Bcl-2, upregulation of Bax, and cell apoptosis. Pretreatment of PC12 cells with baicalein inhibited H2O2-induced cell viability loss, intracellular reactive oxygen species generation, and lipid peroxidation in a dose-dependent manner. Meanwhile, baicalein potentially inhibited H2O2-induced cell apoptosis characterized with the DNA fragment. And the mitochondrial pathway involving the mitochondrial dysfunction associated with cell apoptosis including membrane potential loss, the release of cytochrome c, the downregulation of Bcl-2, upregulation of Bax induced by H2O2 were also abrogated in the presence of baicalein. Taken together, these results suggest that baicalein can block H2O2-induced apoptosis by prevention of oxidative stress as well as regulation of Bcl-2 family members and suppression of mitochondria dysfunction, which might be beneficial for the treatment of oxidative stress in aging and age-associated neurodegenerative diseases.

Abstract: Schizophrenia is a multifactorial disease with changes in immunological system Such changes are the result of cytokine-level disturbances connected with cytokine gene polymorphisms However, research about cytokine gene polymorphisms in schizophrenia has been surprisingly limited and ambiguous The aim of the study was to identify whether polymorphisms of interleukin (IL)-6 and IL-10 are risk factors for the development of paranoid schizophrenia in case-control study IL-6 (−174G/C; rs 1800795) and IL-10 (−1082G/A; rs 1800896) promoter polymorphisms in patients with paranoid schizophrenia and healthy individuals were genotyped using polymerase chain reaction–restriction fragment length polymorphism method Differences in IL-6 and IL-10 promoter haplotypes may play an important role in determining the transcription level for IL-6 and IL-10 genes in schizophrenic patients The presence of allele C at position −174 of IL-6 promoter sequence may correlate with increasing risk of paranoid schizophrenia in the Polish population, but research on a broadened group of people is needed The presence of allele G at position −1082 of IL-10 promoter sequence correlates with increasing risk of paranoid schizophrenia in the Polish population The coexistence of genotype GG at position −1082 of IL-10 promoter sequence and genotype GC at position −174 of IL-6 promoter sequence correlates with increasing risk of paranoid schizophrenia in the Polish population

Abstract: Memogain® (Gln-1062) is an inactive pro-drug of galantamine, the latter being a plant alkaloid approved for the treatment of mild to moderate Alzheimer’s disease. Memogain has more than 15-fold higher bioavailability in the brain than the same doses of galantamine. In the brain, Memogain is enzymatically cleaved to galantamine, thereby regaining its pharmacological activity as a cholinergic enhancer. In animal models of drug-induced amnesia, Memogain produced several fold larger cognitive improvement than the same doses of galantamine, without exhibiting any significant levels of gastrointestinal side effects that are typical for the unmodified drug and other inhibitors of cholinesterases, such as donepezil and rivastigmin. In the ferret, dramatically reduced emetic and behavioral responses were observed when Memogain was administered instead of galantamine. Based on these and other preclinical data, Memogain may represent an advantageous drug treatment for Alzheimer’s disease, combining much lesser gastrointestinal side effects and considerably higher potency in enhancing cognition, as compared to presently available drugs.

Abstract: Stem cell-based therapy holds great potential for future treatment of multiple sclerosis (MS). Bone marrow mesenchymal stem cells (MSCs) were previously reported to ameliorate symptoms in mouse MS models (experimental autoimmune encephalomyelitis, EAE). In this study, we induced MSCs to differentiate in vitro into neurotrophic factor-producing cells (NTFCs). Our main goal was to examine the clinical use of NTFCs on EAE symptoms. The NTFCs and MSCs were transplanted intracerebroventricularly (ICV) to EAE mice. We found that NTFCs transplantations resulted in a delay of symptom onset and increased animal survival. Transplantation of MSCs also exerted a positive effect but to a lesser extent. In vitro analysis demonstrated the NTFCs' capacity to suppress mice immune cells and protect neuronal cells from oxidative insult. Our results indicate that NTFCs-transplanted ICV delay disease symptoms of EAE mice, possibly via neuroprotection and immunomodulation, and may serve as a possible treatment to MS.

Abstract: Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) are two closely related peptides, which can activate protein kinase A (PKA). At least three receptors for PACAP and VIP have been identified. The PACAP-specific receptor, PAC1 receptor, exhibits a higher affinity for PACAP than VIP, whereas VIP receptors, VPAC1-R and VPAC2-R, have similar affinities for PACAP and VIP. Both PACAP/VIP and their cognate receptors are highly expressed in the brain, including the hippocampus. Recently, their roles in the regulation of synaptic transmission have begun to emerge. PACAP/VIP can signal through different pathways to regulate N-methyl-d-aspartate (NMDA) receptors in CA1 pyramidal cells. The activation of VPAC1/2-Rs increases evoked NMDA currents via the cyclic AMP/PKA pathway. However, the activation of PAC1-R stimulates a PLC/PKC/Pyk2/Src signaling pathway to enhance NMDA receptor function in hippocampal neurons. Furthermore, different concentrations of PACAP induce different effects on the both α-amino-3-hydroxy-5-isoxazole-propionic acid-evoked current and basal synaptic transmission by activating different receptors. Their roles in learning and memory are also demonstrated using transgenic mice and pharmacological methods.

Abstract: Wild-type and α5 null mutant mice were used to identify nicotinic cholinergic receptors (nAChRs) that mediate α-conotoxin MII (α-CtxMII)-resistant dopamine (DA) release from striatal synaptosomes. Concentration–effect curves for ACh-stimulated release (20 s) were monophasic when wild-type synaptosomes were assayed but biphasic with synaptosomes from the α5 null mutant. Deleting the α5 gene also resulted in decreased maximal ACh-stimulated α-CtxMII-resistant DA release. When a shorter perfusion time (5 s) was used, biphasic curves were detected in both wild-type and α5 null mutants, indicative of high- and low-sensitivity (HS and LS) activity. In addition, DHβE-sensitive (HS) and DHβE-resistant (LS) components were found in both genotypes. These results indicate that α-CtxMII-resistant DA release is mediated by α4α5β2, (α4)2(β2)3 (HS), and (α4)3(β2)2 (LS) nAChRs.

Abstract: Dysfunctional cholinergic transmission is thought to underlie, at least in part, memory impairment and cognitive deficits in Alzheimer’s disease (AD). However, it is still unclear whether this is a consequence of the loss of cholinergic neurons and elimination of nicotinic acetycholine receptors (nAChRs) in AD brain or of a direct impact of molecular interactions of the amyloid-β (Aβ) peptide with nAChRs, leading to dysregulation of receptor function. This review examines recent progress in our understanding of the roles of nicotinic receptors in mechanisms of synaptic plasticity, molecular interactions of Aβ with nAChRs, and how Aβ-induced dysregulation of nicotinic receptor function may underlie synaptic failure in AD.

Abstract: Application of adult bone marrow stromal cells (BMSCs) provides therapeutic benefits to the treatment of neurological insults. The aim of this study was to explore the potential of nonhematopoietic BMSCs to produce soluble factors and stimulate signaling pathways in neurons that mediate trophic effects. A combination of enzyme-linked immunosorbent assay and two-dimensional gel electrophoresis coupled with mass spectrometry showed that the BMSCs released into the culture medium an array of soluble factors such as nerve growth factor, brain-derived neurotrophic factor, basic fibroblast growth factor, and ciliary neurotrophic factor, which have been shown to exhibit potent neurotrophic effects on neural cells. Immunochemistry, cell viability assay, and quantitative real-time RT-PCR collectively showed that neurite outgrowth and neurogenesis in cultured rat dorsal root ganglion (DRG) explants and neurons were enhanced after they were cocultured with rat BMSCs. Western blot analysis revealed that BMSC-conditioned medium activated phosphorylation of mitogen-activated protein kinase/extracellular signal-regulated protein kinase and/or phosphoinositide 3-kinase/serine/threonine kinase (PI3K/Akt) in primary culture of rat DRG neurons, which suggested that BMSCs trigger endogenous survival signaling pathways in neurons through their secreted soluble factors. Our data help to elucidate the mechanisms by which BMSCs function as a cell therapy agent in peripheral nerve regeneration.

Abstract: The aim of this study was to investigate the involvement of transient receptor potential vanilloid 1 (TRPV1) receptors in oral dextran sulfate sodium-induced (DSS) colitis using TRPV1 knockout mice and their wild-type C57BL/6 counterparts. DSS (2% or 5%) was administered orally ad libitum for 7 days; the controls received tap water. Animal weight, stool consistency, and blood content were scored every day to calculate the disease activity index (DAI). After sacrificing the mice on day 7, the colons were cut into three equal segments (proximal, intermediate, and distal) for histology, myeloperoxidase (MPO), and cytokine measurements. In the 2% DSS-treated group, the lack of TRPV1 receptors decreased the DAI. Each colon segment of wild-type animals showed more than two-fold increase of MPO activity and more severe histological changes compared to the knockouts. This difference was not observed in case of 5% DSS, when extremely severe inflammation occurred in both groups. IL-1β production was not altered by the absence of TRPV1. In conclusion, activation of TRPV1 channels enhances the clinical symptoms, histopathological changes, and neutrophil accumulation induced by 2% DSS. Elucidating the modulator role of TRPV1 channels in inflammatory bowel diseases may contribute to the development of novel anti-inflammatory drugs for their therapy.

Abstract: Use of tobacco products contributes to hundreds of thousands of premature deaths and untold millions of dollars in health care costs in this country each year. Nicotine is the principal neuroactive component in tobacco, but, despite ongoing research efforts, the cellular basis of its effects on behavior remains unclear. Efforts to resolve this conundrum have focused on the mesoaccumbens dopamine system, which contributes to the rewarding effects of many addictive drugs, including nicotine. The goal of this review is to outline recent advances and highlight some of the important unanswered questions regarding nicotine's effects on neuronal excitability and synaptic plasticity within the brain reward pathways.

Abstract: In our previous report, four limonoids, obacunone, limonin, fraxinellone, and calodendrolide, isolated from Dictamnus dasycarpus showed significant neuroprotective activity against glutamate toxicity in primary cultured rat cortical cells. This study investigated neuroprotective mechanism of these compounds using the same in vitro culture system. These four compounds showed significant neuroprotective activity at the concentration of 0.1 μM. They effectively inhibited calcium influx and overproduction of cellular nitric oxide and reactive oxygen species accompanied by glutamate-induced neurotoxicity. In addition, these compounds significantly preserved mitochondrial membrane potential and activities of antioxidative enzymes. Our results showed that obacunone, limonin, fraxinellone, and calodendrolide significantly protect primary culture cortical cells against glutamate-induced toxicity by preserving the antioxidant defense system. These compounds might offer potential drug development candidate for various neurodegenerative diseases involved with glutamate.

Abstract: Ubiquitination is a key event for protein degradation by the proteasome system, membrane protein internalization, and protein trafficking among cellular compartments. Few data are available on the role of the ubiquitin–proteasome system (UPS) in the trafficking of neuronal nicotinic acetylcholine receptors (nAChRs). Experiments conducted in neuron-like differentiated rat pheochromocytoma cells (PC12 cells) show that the α3, β2, and β4 nAChR subunits are ubiquitinated and that their ubiquitination is necessary for degradation. A 24-h treatment with the proteasome inhibitor PS-341 increased the total levels of α3 and the two β subunits in both whole cell lysates and fractions enriched for the ER/Golgi compartment. nAChR subunit upregulation was also detected in plasma membrane-enriched fractions. Inhibition of the lysosomal degradation machinery by E-64 had a significantly smaller effect on nAChR turnover. The present data, together with previous results showing that the α7 nAChR subunit is a target of the UPS, point to a prominent role of the proteasome in nAChR trafficking.

Abstract: Glucocorticoids regulate a wide variety of functions, including synaptic plasticity, hypothalamic-pituitary-adrenal axis activation, conditional fear learning, metabolism, and sensitization to drugs of abuse. The diurnal secretion of glucocorticoids, driven by the mammalian master clock located in the suprachiasmatic nucleus of the hypothalamus, has been shown to induce and entrain clock gene expression in peripheral tissues. However, little attention has been given to the form and function of centrally located subordinate oscillators, and the synchronizing factors that influence them. Here we review findings that implicate glucocorticoids in the circadian regulation of clock genes in select oscillators in the limbic forebrain and propose mechanisms whereby glucocorticoids can feed back on rhythms downstream from the master clock and possibly alter the functional output of these nuclei.

Abstract: The aim of this study was to explore the modulation by α7 nicotinic receptors (nAChRs) of dopamine and glutamate release in the rat prefrontal cortex where these receptors are implicated in attentional processes and are therapeutic targets for cognitive deficits. The presence of presynaptic α7 nAChRs on glutamate terminals is supported by the ability of the subtype-selective agonist Compound A to evoke [3H]D-aspartate release from synaptosomes: This response was potentiated by the selective allosteric potentiator PNU-120596 and blocked by αbungarotoxin. Compound A also evoked dopamine overflow in the prefrontal cortex in vivo, and this was potentiated by PNU-120596. α7 nAChR-evoked [3H]dopamine release from tissue prisms in vitro was blocked by antagonists of NMDA and AMPA receptors. These data are consistent with a model in which α7 nAChRs present on glutamate terminals increase glutamate release that (1) contributes to presynaptic facilitation and synaptic plasticity and (2) co-ordinately enhances dopamine release from neighbouring boutons.

Abstract: Pituitary adenylate cyclase-activating polypeptide (PACAP) is a multifunctional peptide that has been shown to be neuroprotective following a diverse range of cell injuries. Although several mechanisms regulating this effect have been reported, no direct evidence has linked PACAP to the regulation of oxidative stress, despite the fact that oxidative stress is a factor in the injury progression that occurs in most models. In the present study, we investigated the plasma oxidative metabolite and anti-oxidation potential levels of PACAP-deficient mice, as well as those of wild-type animals treated with PACAP38. These were assayed by the determination of Reactive Oxidative Metabolites (d-ROMs) and the Biological Anti-oxidant Potential (BAP) using the Free Radical Electron Evaluator system. We also investigated the direct radical scavenging potency of PACAP38 and the functional role of its receptor in the regulation of oxidative stress by PACAP, by using vasoactive intestinal peptide (VIP) and the PACAP receptor antagonist, PACAP6–38. Although younger PACAP null mice displayed no significant effect, greater d-ROMs and lower BAP values were recorded in older animals than in their wild-type littermates. Intravenous injection of PACAP38 in wild-type mice decreased the plasma d-ROMs and BAP values in a dose-dependent manner. These effects were not reproduced using VIP and were abolished by co-treatment with PACAP38 and the PAC1R antagonist PACAP6-38. Taken together, these results suggest that PACAP plays an important role in the physiological regulation of oxidative stress.

Abstract: Interleukin-15 (IL-15) is a cytokine produced in the normal brain that acts on its specific receptor IL-15Rα and co-receptors IL-2Rβ and IL-2Rγ in neuronal cells. The functions of the cerebral IL-15 system, however, are not yet clear. To test the hypothesis that IL-15Rα regulates metabolic activity and body temperature, we quantified the specific metabolic phenotype of IL-15Rα knockout mice. These normal-appearing mice were leaner with lower fat composition. During the entire circadian cycle, the knockout mice had a significantly higher acrophase in locomotor activity and heat dissipation. During the light phase, there was significantly greater food intake, oxygen consumption, and carbon dioxide production. The difference in the dark and light phases suggests that IL-15Rα participates in circadian rhythm regulation. The higher oxygen consumption in the light phase indicates adaptive thermogenesis in the knockout mice. The body temperature of the receptor knockout mice was significantly higher than the control in the light phase, and this was mainly caused by a large difference occurring between 0600 and 0900 h. In addition to the metabolic chamber studies and circadian rhythm analyses, qPCR of hypothalamic homogenates indicated higher mRNA expression of orexin and transient receptor potential vanilloid 4 cation channels. Consistent with a direct role of IL-15Rα in the hypothalamus, IL-15 treatment of the wild-type mice induced c-Fos expression in the preoptic area. We conclude that activation of hypothalamic neurons by IL-15 in mice contributes to thermoregulation and modifies the metabolic phenotype.

Abstract: Parkinson's disease (PD) is a severe neurodegenerative disorder characterised by loss of dopaminergic neurons of the substantia nigra. The pathological hallmarks are cytoplasmic inclusions termed Lewy bodies consisting primarily of aggregated α-synuclein (αSN). Different lines of transgenic mice have been developed to model PD but have failed to recapitulate the hallmarks of this disease. Since treatment of rodents with the pesticide rotenone can reproduce nigrostriatal cell loss and other features of PD, we aimed to test chronic oral administration of rotenone to transgenic mice over-expressing human αSN with the A53T mutation. Initial assessment of this transgenic line for compensatory molecular changes indicated decreased brain β-synuclein expression and significantly increased levels of the PD-associated oxidative stress response protein, DJ-1, and the E3 ubiquitin ligase enzyme, Parkin. Rotenone treatment of 30 mg/kg for 25 doses over a 35-day period was tolerated in the transgenic mice and resulted in decreased spontaneous locomotor movement and increased cytoplasmic αSN expression. The mitochondrial Parkinson's-associated PTEN-induced kinase 1 protein levels were also increased in transgenic mouse brain after rotenone treatment; there was no change in brain dopamine levels or nigrostriatal cell loss. These hA53T αSN transgenic mice provide a useful model for presymptomatic Parkinson's features and are valuable for study of associated compensatory changes in early Parkinson's disease stages.

Abstract: The capability of the tertiary oximes, monoisonitrosoacetone (MINA) and diacetylmonoxime (DAM), to reactivate acetylcholinesterase (AChE) inhibited by sarin (GB) in the blood, brain, and peripheral tissues of guinea pigs was compared with that of the quaternary oximes 2-PAM, HLo7, and MMB-4. Animals were injected subcutaneously (s.c.) with 1.0 × LD50 of GB and treated intramuscularly (i.m.) 5 min later with one of these oximes. Sixty minutes after GB exposure, tissues were collected for AChE analysis. At low doses, MINA and DAM produced significant increases in AChE activity in all brain areas examined, but no significant AChE reactivation in peripheral tissues or blood. At higher doses, MINA and DAM increased AChE activity in the brain, peripheral tissues, and blood. In contrast, the quaternary oximes produced significant reactivation in peripheral tissues and blood AChE, but no significant reactivation of brain AChE. In another study, animals were pretreated i.m. with pyridostigmine 30 min prior to s.c. challenge with 2.0 × LD50 of GB and treated i.m. 1 min later with atropine sulfate (2.0 mg/kg), plus a varied dose of oximes. MINA and DAM prevented or terminated GB-induced seizure activity and protected against GB lethality in a dose-dependent fashion. In contrast, none of the quaternary oximes prevented or stopped GB-induced seizures. Thus, tertiary oximes reactivated AChE in the brain, improved survival, and terminated seizures following GB intoxication.

Abstract: Gliomas are the most common type of primary brain tumors. Despite the improvement in current treatments for gliomas, including surgical resection, radiation, and chemotherapy, there has been very little progress in curing this kind of disease. Stat3 is a member of signal transducer and activator of transcription family. It plays an important role in regulating cell survival, invasion, and apoptosis. This study investigated the influence of low-level expression of Stat3 on invasion and apoptosis in U251 cells. Our data showed that Stat3 is constitutively expressed in human gliomas cell line U251. The invasion activity in U251 cells was weakened and the apoptosis in U251 cells was induced after down-regulation of Stat3. In addition, down-regulation of Stat3 can suppress the expression of MMP-2, Bcl-xL and survivin but not 67LR. These results further indicate that Stat3 plays a key role in the invasion and apoptosis of human glioma cell line U251.

Abstract: Traumatic brain injury (TBI) elicits a sequence of complex biochemical changes including oxidative stress, oedema, inflammation and excitotoxicity These factors contribute to the high morbidity and mortality following TBI, although their underlying molecular mechanisms remain poorly understood Transient receptor potential melastatin 2 (TRPM2) is a non-selective cation channel, highly expressed in the brain and immune cells Recent studies have implicated TRPM2 channels in processes involving oxidative stress, inflammation and cell death However, no studies have investigated the role of TRPM2 in TBI pathophysiology In the present study, we have characterised TRPM2 mRNA and protein expression following experimental TBI Adult male Sprague Dawley rats were injured using the impact-acceleration model of diffuse TBI with survival times between 5 and 5 days Real-time RT-PCR (including reference gene validation studies) and semi-quantitative immunohistochemistry were used to quantify TRPM2 mRNA and protein levels, respectively, following TBI Significant increases in TRPM2 mRNA and protein expression were observed in the cerebral cortex and hippocampus of injured animals, suggesting that TRPM2 may contribute to TBI injury processes such as oxidative stress, inflammation and neuronal death Further characterisation of how TRPM2 may contribute to TBI pathophysiology is warranted

Abstract: Control of seizure activity is critical to survival and neuroprotection following nerve agent exposure. Extensive research has shown that three classes of drugs, muscarinic antagonists, benzodiazepines, and N-methyl-d-aspartate antagonists, are capable of moderating these seizures. This study began to map the neural areas in rat brain that respond to these three drug classes resulting in anticonvulsant effects. Drugs of each class (scopolamine, midazolam, MK-801) were evaluated for their ability to prevent sarin-induced seizures when injected into specific brain areas (lateral ventricle, anterior piriform cortex, basolateral amygdala, area tempestas). Animals were pretreated by microinjection with saline or a dose of drug from one of the three classes 30 min prior to receiving 150 μg/kg sarin, subcutaneously, followed by 2.0 mg/kg atropine methylnitrate, intramuscularly. Animals were then returned to their cages, where electroencephalographic activity was monitored for seizures. Anticonvulsant effective doses (ED50) were determined using an up–down dosing procedure over successive animals. Scopolamine provided anticonvulsant effects in each area tested, while midazolam was effective in each area except the lateral ventricle. MK-801 was only effective at preventing seizures when injected into the basolateral amygdala or area tempestas. The results show a unique neuroanatomical and pharmacological specificity for control of nerve agent-induced seizures.

Abstract: Pituitary adenylate cyclase-activating polypeptide (PACAP) is present in the gastrointestinal tract and plays a central role in the intestinal physiology, mainly in the secretion and motility. The aim of our study was to compare the ischemic injury in wild-type and PACAP-38 knockout mice following warm mesenteric small bowel ischemia. Warm ischemia groups were designed with occlusion of superior mesenteric artery for 1, 3, and 6 h in wild-type (n = 10 in each group) and PACAP-38 knockout (n = 10 in each group) mice. Small bowel biopsies were collected after laparotomy (control) and at the end of the ischemia periods. To determine oxidative stress parameters, malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase (SOD) were measured. Tissue damage was analyzed by qualitative and quantitative methods on hematoxylin/eosin-stained sections. In PACAP-38 knockout animals, tissue MDA increased significantly after 3 and 6 h ischemia (133.97 ± 6,2; 141.86 ± 5,8) compared to sham-operated (100.92 ± 3,6) and compared to wild-type results (112.8 ± 2,1; 118.4 ± 1.03 μmol/g, p < 0.05). Meanwhile, tissue concentration of GSH and activity of SOD decreased significantly in knockout mice compared to wild-type form (GSH, 795.97 ± 10.4; 665.1 ± 8,8 vs. 893.23 ± μmol/g; SOD, 94.4 ± 1.4; 81.2 ± 3.9 vs. 208.09 ± 3,7 IU/g). Qualitative and quantitative histological results showed destruction of the mucous, submucous layers, and crypts in knockout mice compared to wild-type tissues. These processes correlated with the warm ischemia periods. Our present results propose an important protective effect of endogenous PACAP-38 against intestinal warm ischemia, which provides basis for further investigation to elucidate the mechanism of this protective effect.

Abstract: Schizophrenia is ranked among multifactor diseases in whose pathogenesis, besides environmental factors, an interplay of functional polymorphisms of a larger number of candidate genes is involved. Neurodevelopmental abnormities are among the most accepted hypotheses in the etiology of schizophrenia. Recently, the role of oligodendrocytes in the development of the cortex has been cited repeatedly. During their various phases of differentiation oligodendrocytes present on their surfaces diverse receptors, among others the μ-opioid receptor (OPRM1). The study was focused on the relationship between the functional A118G polymorphism of the OPRM1 gene (rs1799971) and schizophrenia in groups of 130 male patients and 452 male controls. An association study revealed yet unpublished statistically significant difference of allelic and genotypic frequencies between the control and patient groups. According to our present knowledge, we assume that the OPRM1 gene polymorphism can influence the myelination of CNS neurons through regulations of expression of OPRM1 receptors on surfaces of oligodendrocytes. The neuronal myelination seems to be one of the important factors in the pathogenesis of schizophrenia.

Abstract: Cuprizone intoxication is a commonly used model of demyelination that allows the temporal separation of demyelination and remyelination. The underlying biochemical alterations leading to demyelination, using this model, remain unclear and may be multifold. Analysis of proteomic changes within the brains of cuprizone-exposed animals may help elucidate key cellular processes. In the current study, we report the results of the liquid chromatography tandem mass spectrometry analysis of total protein from the brain hemispheres of control and toxin-exposed mice at 6 weeks of exposure and after 3 and 6 weeks of recovery to identify protein changes during the remyelination phase. We found that at 6 weeks of cuprizone exposure, myelin proteins were reduced compared to controls and increased throughout the course of recovery, as expected. In contrast, other protein groups, such as proteins related to mitochondrial function, were increased at 6 weeks of treatment compared to untreated controls and returned toward control levels following withdrawal of toxin. These results suggest that a global proteomic analysis of the brain tissue of cuprizone-treated mice can identify changes related to the demyelination/remyelination process.

Abstract: Urothelium-specific overexpression of nerve growth factor (NGF) in the urinary bladder of transgenic mice stimulates neuronal sprouting or proliferation in the urinary bladder, produces urinary bladder hyperreflexia, and results in increased referred somatic hypersensitivity. Additional NGF-mediated changes might contribute to the urinary bladder hyperreflexia and pelvic hypersensitivity observed in these transgenic mice such as upregulation of neuropeptide/receptor systems. Chronic overexpression of NGF in the urothelium was achieved through the use of a highly urothelium-specific, uroplakin II promoter. In the present study, we examined pituitary adenylate cyclase activating polypeptide (PACAP), vasoactive intestinal polypeptide (VIP), and associated receptor (PAC1, VPAC1, VPAC2) transcripts or protein expression in urothelium and detrusor smooth muscle and lumbosacral dorsal root ganglia in NGF-overexpressing and littermate wildtype mice using real-time quantitative reverse transcription-polymerase chain reaction and immunohistochemical approaches. Results demonstrate upregulation of PAC1 receptor transcript and PAC1-immunoreactivity in urothelium of NGF-OE mice whereas PACAP transcript and PACAP-immunoreactivity were decreased in urothelium of NGF-OE mice. In contrast, VPAC1 receptor transcript was decreased in both urothelium and detrusor smooth muscle of NGF-OE mice. VIP transcript expression and immunostaining was not altered in urinary bladder of NGF-OE mice. Changes in PACAP, VIP, and associated receptor transcripts and protein expression in micturition pathways resemble some, but not all, changes observed after induction of urinary bladder inflammation known to involve NGF production.

Abstract: The cyclical expression of the clock protein PERIOD2 (PER2) in select regions of the limbic forebrain is contingent upon the rhythmic secretion of the adrenal glucocorticoid, corticosterone. Daily rhythmic PER2 expression in the oval nucleus of the bed nucleus of the stria terminalis (BNSTov) and the central nucleus of the amygdala (CEA) is abolished with the removal of the adrenal glands but restored with rhythmic hormone replacement via the drinking water at a time corresponding to the endogenous peak of circulating glucocorticoids. Here, we investigated the effects of serial or acute systemic injections of corticosterone on the expression of PER2 in the BNSTov and CEA of both adrenalectomized (ADX) and intact rats. We sought to determine whether there is a temporal window of corticosterone sensitivity by delivering the hormone at a time corresponding to trough levels of circulating glucocorticoids, at lights on. We found that daily morning injections of corticosterone induced PER2 expression in the BNSTov and CEA of ADX rats, with levels peaking 1 h after injection. In intact rats, daily morning injections significantly upregulated the expression of PER2 in the BNSTov and CEA 1 h after injection and dampened the evening peak, while a single injection abolished the rhythm of PER2 expression in the CEA but had no effect on PER2 in the BNSTov. Our findings suggest that despite the potential masking effect of signals from the light-entrained master clock, daytime chronic and acute corticosterone administration can alter the rhythmic expression of PER2 in the BNSTov and CEA, and that the response is region-specific and dependent on the duration of treatment.