Number Of Positive Neurons Research Articles

The Glycolysis Inhibitor 2-Deoxy-D-Glucose Exerts Different Neuronal Effects at Circuit and Cellular Levels, Partially Reverses Behavioral Alterations and does not Prevent NADPH Diaphorase Activity Reduction in the Intrahippocampal Kainic Acid Model of Temporal Lobe Epilepsy.

Temporal lobe epilepsy is the most drug-resistant type with the highest incidence among the other focal epilepsies. Metabolic manipulations are of great interest among others, glycolysis inhibitors like 2-deoxy d-glucose (2-DG) being the most promising intervention. Here, we sought to investigate the effects of 2-DG treatment on cellular and circuit level electrophysiological properties using patch-clamp and local field potentials recordings and behavioral alterations such as depression and anxiety behaviors, and changes in nitric oxide signaling in the intrahippocampal kainic acid model. We found that epileptic animals were less anxious, more depressed, with more locomotion activity. Interestingly, by masking the effect of increased locomotor activity on the parameters of the zero-maze test, no altered anxiety behavior was noted in epileptic animals. However, 2-DG could partially reverse the behavioral changes induced by kainic acid. The findings also showed that 2-DG treatment partially suppresses cellular level alterations while failing to reverse circuit-level changes resulting from kainic acid injection. Analysis of NADPH-diaphorase positive neurons in the CA1 area of the hippocampus revealed that the number of positive neurons was significantly reduced in dorsal CA1 of the epileptic animals and 2-DG treatment did not affect the diminishing effect of kainic acid on NADPH-d+ neurons in the CA1 area. In the control group receiving 2-DG, however, an augmented NADPH-d+ cell number was noted. These data suggest that 2-DG cannot suppress epileptiform activity at the circuit-level in this model of epilepsy and therefore, may fail to control the seizures in temporal lobe epilepsy cases.

FeNi3 Nanoparticle for the Localization of Temporal Lobe Epilepsy by MRI

From the perspective of targeting factors, iron acetylacetonate and nickel acetylacetonate were used as major materials, and oleylamine was used as a solvent. Through thermal decomposition, the uniformly distributed nanoparticle FeNi3 was obtained. Then, the α-methyltryptophan (AMT) was used to modify FeNi3, thereby the material (FeNi3-AMT) would be biocompatible. The prepared material was used as a targeting factor to explore whether it could target the epileptogenic focus in temporal lobe epilepsy model rats. In the experiment, the animal models of temporal lobe epilepsy were constructed by using the lithium chloride-pirocarpine method. According to the injection of the nuclear magnetic factor, the models were divided into the FeNi3 group, the FeNi3-AMT group, and the saline group. The model rats received intravenous injections 48 hours after the onset of epilepsy. The activity of the epileptic seizure sites before and after injection, the penetration of nanoparticles, and the toxic and side effects of the material were compared. The results showed that the rat models of temporal lobe epilepsy were successfully constructed (the success rate was more than 85%). Meanwhile, the epilepsy lesions of the rat models added with nanoparticles were darker (P < 0.05). The staining of rat brain sections confirmed the distribution of iron particles. In the FeNi3-AMT group, there were more iron particles distributed (P < 0.05). In addition, various abnormal neurons appeared in the hippocampus of the three groups, and there was no significant difference between the different groups (P < 0.05). There was no significant difference in the number of positive neurons in the CA3 region of the brain between different groups (P < 0.05). However, the imaging effect based on FeNi3-AMT was more prominent (P < 0.05), which confirmed that the FeNi3-AMT group had better targeting location effects. The study confirmed that the iron nano alloy particle material had excellent application values in the localization of temporal lobe epilepsy.

ChABC infusions into medial prefrontal cortex, but not posterior parietal cortex, improve the performance of rats tested on a novel, challenging delay in the touchscreen TUNL task.

Perineuronal nets (PNNs) are specialized extracellular matrix structures that surround subsets of neurons throughout the central nervous system (CNS). They are made up of chondroitin sulfate proteoglycans (CSPGs), hyaluronan, tenascin-R, and many other link proteins that together make up their rigid and lattice-like structure. Modulation of PNNs can alter synaptic plasticity and thereby affect learning, memory, and cognition. In the present study, we degraded PNNs in the medial prefrontal (mPFC) and posterior parietal (PPC) cortices of Long–Evans rats using the enzyme chondroitinase ABC (ChABC), which cleaves apart CSPGs. We then measured the consequences of PNN degradation on spatial working memory (WM) with a trial-unique, non-matching-to location (TUNL) automated touchscreen task. All rats were trained with a standard 6 sec delay and 20 sec inter-trial interval (ITI) and then tested under four different conditions: a 6 sec delay, a variable 2 or 6 sec delay, a 2 sec delay with a 1 sec ITI (interference condition), and a 20 sec delay. Rats that received mPFC ChABC treatment initially performed TUNL with higher accuracy, more selection trials completed, and fewer correction trials completed compared to controls in the 20 sec delay condition but did not perform differently from controls in any other condition. Rats that received PPC ChABC treatment did not perform significantly differently from controls in any condition. Posthumous immunohistochemistry confirmed an increase in CSPG degradation products (C4S stain) in the mPFC and PPC following ChABC infusions while WFA staining intensity and parvalbumin positive neuron number were decreased following mPFC, but not PPC, ChABC infusions. These findings suggest that PNNs in the mPFC play a subtle role in spatial WM, but PNNs in the PPC do not. Furthermore, it appears that PNNs in the mPFC are involved in adapting to a challenging novel delay, but that they do not play an essential role in spatial WM function.

Reversible Functional Changes Evoked by Anodal Epidural Direct Current Electrical Stimulation of the Rat Auditory Cortex.

Rat auditory cortex was subjected to 0.1 mA anodal direct current in seven 10-min sessions on alternate days. Based on the well-known auditory cortex control of olivocochlear regulation through corticofugal projections, auditory brainstem responses (ABRs) were recorded as an indirect test of the effectiveness and reversibility of the multisession protocol of epidural stimulation. Increases of 20–30 dB ABR auditory thresholds shown after epidural stimulation reverted back to control levels 10 min after a single session. However, increases in thresholds revert 4 days after multisession stimulation. Less changes in wave amplitudes and threshold shifts were shown in ABR recorded contralaterally to the electrically stimulated side of the brain. To assess tissue effects of epidural electric stimulation on the brain cortex, well characterized functional anatomical markers of glial cells (GFAP/astrocytes and Iba1/microglial cells) and neurons (c-Fos) were analyzed in alternate serial sections by quantitative immunocytochemistry. Restricted astroglial and microglial reactivity was observed within the cytoarchitectural limits of the auditory cortex. However, interstitial GFAP overstaining was also observed in the ventricular surface and around blood vessels, thus supporting a potential global electrolytic stimulation of the brain. These results correlate with extensive changes in the distribution of c-Fos immunoreactive neurons among layers along sensory cortices after multisession stimulation. Quantitative immunocytochemical analysis supported this idea by showing a significant increase in the number of positive neurons in supragranular layers and a decrease in layer 6 with no quantitative changes detected in layer 5. Our data indicate that epidural stimulation of the auditory cortex induces a reversible decrease in hearing sensitivity due to local, restricted epidural stimulation. A global plastic response of the sensory cortices, also reported here, may be related to electrolytic effects of electric currents.

Smilagenin Protects Dopaminergic Neurons in Chronic MPTP/Probenecid-Lesioned Parkinson's Disease Models.

Current therapies for Parkinson’s disease (PD) only offer limited symptomatic alleviation but fail to hamper the progress of the disease. Thus, it is imperative to establish new approaches aiming at protecting or reversing neurodegeneration in PD. Recent work elucidates whether smilagenin (abbreviated SMI), a steroidal sapogenin from traditional Chinese medicinal herbs, can take neuroprotective effect on dopaminergic neurons in a chronic model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) conjuncted with probenecid mice. We reported for the first time that SMI significantly improved the locomotor ability of chronic MPTP/probenecid–lesioned mice. SMI increased the tyrosine hydroxylase (TH) positive and Nissl positive neuron number in the substantia nigra pars compacta (SNpc), augmented striatal DA and its metabolites concentration and elevated striatal dopamine transporter density (DAT). In addition, dopamine receptor D2R not D1R was down-regulated by MPTP/probenecid and slightly raised by SMI prevention. What’s more, we discovered that SMI markedly elevated striatal glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) protein levels in SMI prevented mice. And we found that SMI increased GDNF and BDNF mRNA level by promoting CREB phosphorylation in 1-methyl-4-phenylpyridimium (MPP+) treated SH-SY5Y cells. The results illustrated that SMI could prevent the impairment of dopaminergic neurons in chronic MPTP/probenecid-induced mouse model.

Postnatal Development of NPY and Somatostatin-28 Peptidergic Populations in the Human Angular Bundle.

The angular bundle is a white matter fiber fascicle, which runs longitudinally along the parahippocampal gyrus. It is best known for carrying fibers from the entorhinal cortex (EC) to the hippocampus through the perforant and alvear pathways, as well as for carrying hippocampal output to the neocortex, and distributing fibers to polysensory cortex. The angular bundle is already present prenatally at the beginning of the fetal period. Connections between the EC and the hippocampus are established by the 20th gestational week (gw). In the postnatal period, it shows increasing myelination. The angular bundle, as well as other white matter portions of gyral surfaces in the brain, presents interstitial neurons, a remnant of subplate neurons. Those interstitial neurons show neurochemical phenotypes both prenatally and postnatally, among which, neuropeptide Y (NPY) and Somatostatin-28 (SOM-28) peptidergic populations are noticeable, and accompany the fiber connections in the maturation of the hippocampal formation. We sought to investigate the topography of the postnatal distribution and relative density of neurons immunoreactive for NPY or SOM in the angular bundle along the rostrocaudal axis of the hippocampus. The study was carried out in 15 cases, ranging from 35 gws, up to 14 year old. All cases showed positive neurons showing a polygonal or spindle shaped morphology for both peptides, scattered throughout the angular bundle. The highest number of positive neurons appeared around birth and the ensuing weeks. Up to one and a half years, the density of both peptidergic populations decreased slightly. However, cases older than 2 years of age showed a substantial decrease in density of immunolabeled neurons, density that did not showed a minor decrease in density of positive neurons in cases older than 2 years. In addition, a topography from caudal to rostral levels of the angular bundle was detected at all ages. The functional significance of interstitial cells is unknown, but the existence of SOM and NPY peptidergic neurons, presumably inhibitory, in the white matter of the angular bundle, could contribute to the basic wiring of the hippocampal formation, through which autobiographical and spatial memories can begin to be stored in the infant brain.

Distribution of nadph-diaphorase positive structures of olfactory bulb of rats in ontogenesis

Aim: to identify peculiarities of distribution of NADPH-diaphorase (NADPH-d) positive structures in olfactory bulbs of rats of different age.
 Materials and Methods. The study was conducted on 22 white male rats. The object of research was olfactory bulbs of newborn rats – 1-3 days, suckling period – 7, 14, 21 days, infantile – 30 days, juvenile – 60, and mature – 180 days. The study was conducted on cryostat serial sections of olfactory bulbs (20 µm). Nitroxidergic structures were identified by histochemical labelling of NADPH-d (by Hope method). In a standard section, the area of NADPH-diaphorase-positive cells (100 in each case), surface area of glomeruli, the number of positive neurons surrounding a glomerulus, were measured.
 Results. In result of study it was found that in the olfactory bulb of rats of the studied age only groups of superficial and deep short-axon neurons and periglomerular neurons showed positivity to NADPH-d. The end product of reaction was distributed in somas and extensions of a part of cells with the density of distribution depending on the layer of the olfactory bulb and on the age of animals. Besides, positivity to the enzyme was also found in the central parts of glomeruli with distribution of diaphorase depending not on age, but rather on localization of glomeruli.
 Conclusion. Age-related transformations of positive subpopulation of neurons of olfactory bulb indicate active participation of NO in the processes of postnatal differentiation, growth and development of olfactory bulb.

Distribution of nadph-diaphorase positive structures of olfactory bulb of rats in ontogenesis

Aim: to identify peculiarities of distribution of NADPH-diaphorase (NADPH-d) positive structures in olfactory bulbs of rats of different age.
 Materials and Methods. The study was conducted on 22 white male rats. The object of research was olfactory bulbs of newborn rats – 1-3 days, suckling period – 7, 14, 21 days, infantile – 30 days, juvenile – 60, and mature – 180 days. The study was conducted on cryostat serial sections of olfactory bulbs (20 µm). Nitroxidergic structures were identified by histochemical labelling of NADPH-d (by Hope method). In a standard section, the area of NADPH-diaphorase-positive cells (100 in each case), surface area of glomeruli, the number of positive neurons surrounding a glomerulus, were measured.
 Results. In result of study it was found that in the olfactory bulb of rats of the studied age only groups of superficial and deep short-axon neurons and periglomerular neurons showed positivity to NADPH-d. The end product of reaction was distributed in somas and extensions of a part of cells with the density of distribution depending on the layer of the olfactory bulb and on the age of animals. Besides, positivity to the enzyme was also found in the central parts of glomeruli with distribution of diaphorase depending not on age, but rather on localization of glomeruli.
 Conclusion. Age-related transformations of positive subpopulation of neurons of olfactory bulb indicate active participation of NO in the processes of postnatal differentiation, growth and development of olfactory bulb.

Bovine herpesvirus type 5 replication and induction of apoptosis in vitro and in the trigeminal ganglion of experimentally-infected cattle.

Bovine herpesvirus (BoHV) types 1 and 5 are neuroinvasive. Cases of BoHV-1-induced encephalitis are not as frequent as those caused by BoHV-5. In this study, the capability of BoHV-5 to induce apoptosis in cell cultures and in the trigeminal ganglion during acute infection of experimentally-infected cattle was analyzed. Apoptotic changes in cell cultures agree with the ability of the viral strains to replicate in each cell line. Marked differences were observed between the in vitro induction of apoptosis by BoHV-1Cooper and BoHV-5 97/613 strains. Apoptotic neurons were clearly evident in the trigeminal ganglion of BoHV-1-infected calves. For BoHV-5 a fewer number of positive neurons was observed. There is an association between the magnitude of bovine herpesviruses replication and the induction of apoptosis in trigeminal ganglion. These findings suggest that the induction of apoptosis and the innate immune response orchestrate the final outcome of alpha herpesviruses infection of the bovine nervous system.

Effect of Electroacupuncture on Expression of 5-HT7 Receptor in Periaqueductal Gray and Plasma Calcitonin Gene-related Peptide in Migraine Rats

To explore the analgesic effect of electroacupuncture(EA)by modulating 5-hydroxytryptamine 7 (5-HT7) receptor in periaqueductal gray (PAG) and plasma calcitonin gene-related peptide (CGRP). Forty-two male Sprague Dawley (SD) rats were randomly divided into control，model and EA groups, 14 rat in each one. The neurogenic migraine model was established by repeated electrical stimulation on sagittal sinus duramater. Intracranial electrodes were used in the control group without stimuli. The rats in the EA group received EA (0.5－1 mA, 2 Hz/15 Hz) at "Fengchi" (GB 20) for 10 min after dural electrical stimulation, once a day for 6 days. The expression of 5-HT7 receptor in the PAG was assessed by immunofluorescence and Western blot, respectively; plasma CGRP was measured by radioimmunoassay. Compared with the control group, the positive neuron number and protein expression of 5-HT7 receptor in PAG and plasma CGRP increased after model establishment (all P<0.001). The above mentioned indexes were reversed in the EA group compared with those in the model group (the positive neuron number and protein expression of 5-HT7 receptor, P<0.01; plasma CGRP, P<0.05). EA at GB 20 can down-regulate the expression of 5-HT7 receptor in the PAG and reduce the content of plasma CGRP in the rats of migraine.

EFFECT OF ISOFLURANE ON NEUROPATHOLOGY AND COGNITIVE IMPAIRMENT IN THE TRIPLE TRANSGENIC ALZHEIMER’S MOUSE MODEL

This study examines the association between isoflurane mediated effects on neuropathology, cognitive performance, and synaptic physiology in early postnatal and aged triple transgenic Alzheimer's disease (3xTg-AD) mice. Male and female C57BL6/J (NonTg) and 3xTg-AD mice (age: PND 7 and 14+ months) were anesthetized with isoflurane in oxygen/air for 2 hours each day over five consecutive days. Mice from each strain and age groups exposed to just oxygen/air served as controls. Plasma levels of S100β 6 hrs after anesthesia were elevated in both NonTg and 3xTg-AD, which was more profound in the 3xTg-AD mice. Isoflurane increased the number of positive neurons for Aβ deposition and oligomers in 3xTg-AD mice. Morris Water Maze (MWM) test showed that young NonTg and 3xTg-AD mice were slow to learn during reference learning test and performed poorly in short-term and working memory tests compared to age-matched controls. Young 3xTg-AD treated with isoflurane performed significantly worse in these spatial learning tests than the isoflurane-treated NonTg mice. Cognitive impairments in the aged mice were noted in short-term memory test in the aged 3xTg-AD mice and in both strains during the long-term and working memory tests. Extracellular field recordings showed hyperexcitable basal synaptic transmission, unstable LTP, and reduced paired pulse facilitation (PPF) in untreated aged 3xTg-AD mice compared to NonTg mice. Isoflurane depressed basal synaptic transmission, more pronounced in the aged 3xTg-AD group. PPF was significantly reduced in both young and old NonTg and 3xTg-AD mice following isoflurane, but more profound in aged 3xTg-AD mice. Isoflurane impaired LTP in young 3xTg and in both young and aged NonTg mice as reflected in the lack of change in extracellular field potential (fEPSP) slope from baseline. Isoflurane normalized and potentiated fEPSP slope to control levels in aged 3xTg mice . Acute treatment of isoflurane to ex-vivo hippocampal slices from young and aged NonTg and 3xTg-AD mice previously exposed to the same anesthetic in vivo suppressed LTP. Acute application of isoflurane to slices from aged 3xTg-AD mice previously exposed to iso displayed severely reduced LTP. isoflurane-mediated neuropathologic and cognitive defects in AD mice are associated with synaptic pathologies in an age-dependent manner.

Differential Histone Acetylation in Sub-Regions of Bed Nucleus of the Stria Terminalis Underlies Fear Consolidation and Extinction.

ObjectiveThe hallmark of anxiety disorders is excessive fear. Previous studies have suggested that selective neural projections from Basal nucleus of stria terminalis (BNST) to amygdala and vice-versa precisely control the fear learning process. However the exact mechanism how the BNST controls fear consolidation and its extinction is largely unknown. In the present study we observed the changes in the BNST sub-regions following fear conditioning and its extinction.MethodsThe change in the number of positive neurons was determined by immunohistochemistry for Acetyl H3 (Histone 3), Acetyl H4 (Histone 4), cAMP response element binding Protein (CBP) and c-fos in three sub-regions of the BNST namely the anterio-lateral BNST (STLP) and anterio-medial BNST (STMA), and lateral-ventral BNST (STLV) of rats subjected to auditory fear conditioning and extinction.ResultsWe found significant increase in the number of CBP, acetyl H3 and acetyl H4 positive neurons in the STMA and STLV but not in the STLP after fear conditioning. However, following fear extinction the number of CBP, acetyl H3 and acetyl H4 positive neurons increased significantly in the STLP but not in the STMA and STLV. Similar changes were observed in the number of c-fos positive neurons after fear consolidation and extinction.ConclusionThe results from this study suggest that the differential histone acetylation in the different sub-regions of the BNST following fear learning and its extinction may be responsible for changes in the neuronal activation patterns resulting in either fear or less fear.

Gender and age related changes in number of dopaminergic neurons in adult human olfactory bulb

IntroductionDopamine is one of the major brain neurotransmitters, and the loss of dopaminergic neurons in basal ganglia cause motor deficits in Parkinson's disease. We proposed that the difficulty in olfaction observed in the elderly may be due to an alteration in the number of dopaminergic neurons. Materials and methodsSections were taken from olfactory bulbs of post-mortem tissue specimens of 13 humans, males and females, aged from 19 to 63 years (≤35 and ≥50 years), with no history of neurological disorders. The tissues were fixed, embedded, cut on a freezing microtome, and prepared for immunohistochemical analysis using tyrosine hydroxylase (TH) and aromatic l-amino acid decarboxylase (AADC) antibodies. The number of positive neurons was counted. ResultsTH- and AADC-positive cells were present in the glomerular layer. There was no significant difference between the numbers of TH- and AADC-positive cells, in males and females, and in young and elderly individuals. The quantitative analysis revealed that the number of TH- and AADC-positive neurons were significantly higher in males than in females (P<0.05). Moreover, there was a significant increase in the number of TH- and AADC-positive neurons in the olfactory bulbs of the elderly compared with young individuals (P<0.05). ConclusionFactors such as gender and age may affect the number of dopaminergic neurons, and there is a correlation between increased dopaminergic neurons and olfactory performance. Moreover, the increase in dopaminergic cells in the olfactory bulb of the elderly may indicate the existence of rostral migratory stream in adult humans.

Harpagoside ameliorates the amyloid-β-induced cognitive impairment in rats via up-regulating BDNF expression and MAPK/PI3K pathways

So far, no effective disease-modifying therapies for Alzheimer’s disease (AD) aiming at protecting or reversing neurodegeneration of the disease have been established yet. The present work aims to elucidate the effect of Harpagoside (abbreviated HAR), an iridoid glycosides purified from the Chinese medicinal herb Scrophularia ningpoensis, on neurodegeneration induced by β-amyloid peptide (Aβ) and the underlying molecular mechanism. Here we show that HAR exerts neuroprotective effects against Aβ neurotoxicity. Rats injected aggregated Aβ1–40 into the bilateral hippocampus displayed impaired spatial learning and memory ability in a Y-maze test and novel object recognition test, while HAR treatment ameliorated Aβ1–40-induced behavioral deficits. Moreover, administration of HAR increased the expression levels of brain-derived neurotrophic factor (BDNF) and activated the extracellular-regulated protein kinase (ERK) and the phosphatidylinositol 3-kinase (PI3-kinase) pathways both in the cerebral cortex and hippocampus of the Aβ1-40-insulted rat model. Furthermore, in cultured primary cortical neurons, Aβ1–42 induced significant decrease of choline acetyltransferase (ChAT)-positive neuron number and neurite outgrowth length, both of which were dose dependently increased by HAR. In addition, HAR pretreatment also significantly attenuated the decrease of cell viability in Aβ1–42-injured primary cortical neurons. Finally, when K252a, an inhibitor of Trk tyrosine kinases, and a BDNF neutralizing antibody were added to the culture medium 2h prior to HAR addition, the protective effect of HAR on Aβ1–42-induced neurodegeneration in the primary cortical neuron was almost inhibited. Taken together, HAR exerting neuroprotection effect and ameliorating learning and memory deficit appears to be associated, at least in part, with up-regulation of BDNF content as well as activating its downstream signaling pathways, e.g., MAPK/PI3K pathways. It raises the possibility that HAR has potential to be a therapeutic agent against AD.

Neonatal Overfeeding in Female Mice Predisposes the Development of Obesity in their Male Offspring via Altered Central Leptin Signalling.

The prevalence of obesity among child-bearing women has increased significantly. The adverse consequences of maternal obesity on the descendants have been well accepted, although few studies have examined the underlying mechanisms. We investigated whether neonatal overfeeding in female mice alters metabolic phenotypes in the offspring and whether hypothalamic leptin signalling is involved. Neonatal overfeeding was induced by reducing the litter size to three pups per litter, in contrast to normal litter size of 10pups per litter. Normal and neonatally overfed female mice were bred with normal male mice, and offspring of overfeeding mothers (OOM) and control mothers (OCM) were generated. We examined body weight, daily food intake, leptin responsiveness and the number of positive neurones for phosphorylated-signal transducer and activator of transcription 3 (pSTAT3) along with neuropeptide Y (NPY) in the arcuate nucleus of the hypothalamus (ARH) and NPY in the nucleus tractus solitarius (NTS) of the brain stem. The body weight and daily food intake of OOM were significantly higher than those of OCM. Leptin significantly reduced food intake and increased the number of pSTAT3 positive neurones in the ARH of OCM mice, whereas no significant changes in food intake and pSTAT3 neurones were found in leptin-treated OOM mice. The number of NPY neurones in the ARH and NTS of the OOM mice was significantly higher than that of OCM mice. The results of the present study indicate that the obese phenotype from mothers can be passed onto the subsequent generation, which is possibly associated with hypothalamic leptin resistance.

Enhanced electrical responsiveness in the cerebral cortex with oral melatonin administration after a small hemorrhage near the internal capsule in rats.

Intracerebral hemorrhage (ICH) can cause direct brain injury at the insult site and indirect damage in remote brain areas. Although a protective effect of melatonin (ML) has been reported for ICH, its detailed mechanisms and effects on remote brain injury remain unclear. To clarify the mechanism of indirect neuroprotection after ICH, we first investigated whether ML improved motor function after ICH and then examined the underlying mechanisms. The ICH model rat was made by collagenase injection into the left globus pallidus, adjacent to the internal capsule. ML oral administration (15 mg/kg) for 7 days after ICH resulted in significant recovery of motor function. Retrograde labeling of the corticospinal tract by Fluoro-Gold revealed a significant increase in numbers of positive neurons in the cerebral cortex. Immunohistological analysis showed that ML treatment induced no difference in OX41-positive activated microglia/macrophage at day 1 (D1) but a significant reduction in 8-hydroxydeoxyguanosin-positive cells at D7. Neutral red assay revealed that ML significantly prevented H2 O2 -induced cell death in cultured oligodendrocytes and astrocytes but not in neurons. Electrophysiological response in the cerebral cortex area where the number of Fluoro-Gold-positive cells was increased was significantly improved in ML-treated rats. These data suggest that ML improves motor abilities after ICH by protecting oligodendrocytes and astrocytes in the vicinity of the lesion in the corticospinal tract from oxidative stress and causes enhanced electrical responsiveness in the cerebral cortex remote to the ICH pathology.

Quantitative changes of nitrergic neurons during postnatal development of chicken myenteric plexus

Information regarding the development of the enteric nervous system (ENS) is important for understanding the functional abnormalities of the gut. Because fertilized chicken eggs provide easy access to embryos, chicken models have been widely used to study embryonic development of myenteric plexus; however, no study has been focused on the postnatal period. The aim of this study was to perform a qualitative and quantitative analysis of the nitrergic neurons in the myenteric plexus of developing chickens in the postnatal period. Whole-mount preparations of the myenteric plexus were made in 7-d, 15-d, and 40-d old (adult) chickens of either sex (n=15). The myenteric plexus was studied after nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry using light microscopy, digital photography, and Image-Pro Plus 6.0 software. The numbers of positively stained neurons and ganglia were counted in the duodenum, jejunum, ileum, caecum, and colon in the different age groups. Data were expressed as mean±standard deviation (SD), and statistical analysis was performed using a one-way analysis of variance (ANOVA) test. The positively stained neurons showed various morphologies and staining intensities, and formed bead-shaped and U-shaped arrangements in the myenteric plexus. The densities of neurons and ganglia increased with age. However, the number of positive neurons per ganglion increased. The number of NADPH-d-positive neurons was highest in the colon, followed by the ileum, the jejunum, the duodenum, and the caeca in all age groups. Developmental changes in the myenteric plexus of chickens continue in the postnatal period, indicating that the maturation process of the gastrointestinal function is gradual. In addition, no significant difference is happening among different intestinal segments during postnatal development, suggesting that the function of different intestinal segments had been determined after birth.

Transplantation of bone marrow stromal cells enhances nerve regeneration of the corticospinal tract and improves recovery of neurological functions in a collagenase-induced rat model of intracerebral hemorrhage.

The reorganization of brain structures after intracerebral hemorrhage (ICH) insult is crucial to functional outcome. Although the pattern of neuronal rewiring is well-documented after ischemic stroke, the study of brain plasticity after ICH has been focusing on the enhancement of dendritic complexity. Here we hypothesized that functional restoration after ICH involves brain reorganization which may be favorably modulated by stem cell transplantation. In this study, bone marrow stromal cells (BMSCs) were transplanted into the perilesional sites of collagenase-induced ICH in adult rats one day after ICH injury. Forelimb functional recovery was monitored with modified limb placing and vibrissae-elicited forelimb placement tests. Anterograde and retrograde tracing were used to assess the reorganization of bilateral forelimb areas of the sensorimotor cortex. We found that in rats transplanted with BMSCs after ICH injury, axonal sprouting occurred in the contralateral caudal forelimb area of the cortex, and was significantly higher than in ICH rat models that received only the vehicle (P < 0.01). The number of positive neurons in the ipsilateral rostral forelimb area of the cortex of the BMSC group was 1.5-to 4.5-fold greater than in the vehicle group (P < 0.05). No difference was found between the BMSC and vehicle groups in hemispheric atrophy or labeled neurons in the ipsilateral caudal forelimb area (P = 0.193). Scores for improved functional behavior in the BMSC group were in accord with the results from histology. Neuronal plasticity of the denervated corticospinal tract at bilateral forelimb areas of the cortex in the collagenase-induced ICH rat models was significantly enhanced by BMSC transplantation. BMSC transplantation may facilitate functional recovery after ICH injury.

Stress‐induced brain histone H3 phosphorylation: contribution of the intensity of stressors and length of exposure

Expression of c-fos is used for the characterization of brain areas activated by stressors. Recently, some epigenetic markers associated with enhanced transcription have been identified that may be also useful to detect neuronal populations important for the processing of stressors: phosphorylation of histone H3 in serine 10 or 28 (pH3S₁₀ or pH3S₂₈). Then, we compared in rats the response to stress of c-fos and these epigenetic changes. More specifically, we studied the influence of the type of stressor (novel environment vs. immobilization, IMO) and the dynamics of the response to IMO. Stress increased pH3S₁₀ positive neurons, with a more restricted pattern than that of c-fos, both in terms of brain areas activated and number of positive neurons. Changes in pH3S₁₀ showed a maximum at 30 min, then progressively declining in most areas in spite of the persistence of IMO. Moreover, the decline was in general more sensitive than c-fos to the termination of IMO. The pattern of pH3S₂₈ was even more restricted that of pH3S₁₀, but they showed co-localization. The present data demonstrate a more selective pattern of stress-induced histone H3 phosphorylation than c-fos. The factors determining such a selectivity and its biological meaning remain to be studied.

Histochemical Detection of 3β-Hydroxysteroid Dehydrogenase in Neurons of Rat Brain

Here we present the results of histochemical detection of 3β-hydroxysteroid dehydrogenase in neurons of the neocortex, cerebellum, and brainstem. The positive reaction was observed in a low number of neocortical, midbrain, and pontine neurons. The maximum number of positive neurons was detected in the cerebellar cortex (Purkinje cells) and hippocampus.