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Brain Sections (brain + section)
Selected AbstractsIntrauterine proximity to male fetuses affects the morphology of the sexually dimorphic nucleus of the preoptic area in the adult rat brainEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 5 2006Minjuan Pei Abstract Previous studies on polytocous rodents have revealed that the fetal intrauterine position influences its later anatomy, physiology, reproductive performance and behavior. To investigate whether the position of a fetus in the uterus modifies the development of the brain, we examined whether the structure of the sexually dimorphic nucleus of the preoptic area (SDN-POA) of rat brains accorded to their intrauterine positions. Brain sections of adult rats gestated between two male fetuses (2M) and between two female fetuses (2F) in the uterus were analysed for their immunoreactivity to calbindin-D28k, which is a marker of the SDN-POA. The SDN-POA volume of the 2M adult males was greater than that of the 2F adult males, whereas the SDN-POA volume of the 2M and 2F adult females showed no significant difference. This result indicated that contiguous male fetuses have a masculinizing effect on the SDN-POA volume of the male. To further examine whether the increment of SDN-POA volume in adulthood was due to exposure to elevated steroid hormones during fetal life, concentrations of testosterone and 17,-estradiol in the brain were measured with 2M and 2F fetuses during gestation, respectively. On gestation day 21, the concentrations of testosterone and 17,-estradiol in the brain were significantly higher in the 2M male rats as compared with the 2F male rats. The results suggested that there was a relationship between the fetal intrauterine position, hormone transfer from adjacent fetuses and the SDN-POA volume in adult rat brains. [source] Plasma Vasopressin Concentrations and Fos Protein Expression in the Supraoptic Nucleus Following Osmotic Stimulation or Hypovolaemia in the Ovariectomized Rat: Effect of Oestradiol ReplacementJOURNAL OF NEUROENDOCRINOLOGY, Issue 3 2004D. E. Hartley Abstract The set points for vasopressin release in response to increasing plasma osmolality and hypovolaemia alter with reproductive status. Here, we studied stimulated vasopressin release following ovariectomy and oestrogen replacement, neuronal activity being measured in terms of immediate early gene expression. Observations were carried out on three groups of female Sprague-Dawley rats. The first group were ovariectomized. The second group were given a subcutaneous oestrogen implant (20 µg/ml oestradiol-17,) at the time of ovariectomy. The final group were left intact and observations performed at oestrus. Two weeks after ovariectomy, vascular cannulae were implanted under anaesthesia and at least 48 h allowed for recovery before hormone release was stimulated by infusion of 1.5 m NaCl for 90 min, or hypovolaemia induced by the removal of 10 mg/kg body weight taken in 1-ml aliquots. Blood pressure was monitored, and blood samples were taken for determination of packed cell volume and plasma vasopressin and osmolality. After a minimum of 48 h, the challenge was repeated, the rats anaesthetized, and perfused with 4% paraformaldehyde. Brain sections were processed for immunocytochemical detection of Fos protein. Vasopressin release in response to both stimuli was reduced in ovariectomized compared to intact rats and the response could be substantially restored by oestradiol replacement. The number of Fos positive cells in the supraoptic nucleus of oestrogen-replaced rats was significantly higher than in the ovariectomized group and not statistically different from the intact group. [source] Direct analysis of lipids in mouse brain using electrospray droplet impact/SIMSJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 4 2010Daiki Asakawa Abstract Electrospray droplet impact (EDI)/secondary ion mass spectrometry (SIMS) is a new desorption/ionization technique for mass spectrometry in which highly charged water clusters produced from the atmospheric-pressure electrospray are accelerated in vacuum by 10 kV and impact the sample deposited on the metal substrate. EDI/SIMS was shown to enhance intact molecular ion formation dramatically compared to conventional SIMS. EDI/SIMS has been successfully applied to the analysis of mouse brain without any sample preparation. Five types of lipids, i.e. phosphatidylcholine (PC), phosphatidylserine, phosphatidylinositol (PI), galactocerebroside (GC) and sulfatide (ST), were readily detected from mouse brain section. In addition, by EDI/SIMS, six different regions of the mouse brain (cerebral cortex, corpus callosum, striatum, medulla oblongata, cerebellar cortex and cerebellar medulla) were examined. While GCs and STs were found to be rich in white matter, PIs were rich in gray matter. Copyright © 2010 John Wiley & Sons, Ltd. [source] Identification of brain neurons expressing the dopamine D4 receptor gene using BAC transgenic miceEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2006Daniela Noaín Abstract The dopamine D4 receptor (D4R) has received considerable interest because of its higher affinity for atypical antipsychotics, the extremely polymorphic nature of the human gene and the genetic association with attention deficit and hyperactivity disorder (ADHD). Several efforts have been undertaken to determine the D4R expression pattern in the brain using immunohistochemistry, binding autoradiography and in situ hybridization, but the overall published results present large discrepancies. Here, we have explored an alternative genetic approach by studying bacterial artificial chromosome (BAC) transgenic mice that express enhanced green fluorescent protein (EGFP) under the transcriptional control of the mouse dopamine D4 receptor gene (Drd4). Immunohistochemical analysis performed in brain sections of Drd4 -EGFP transgenic mice using an anti-EGFP polyclonal antibody showed that transgenic expression was predominant in deep layer neurons of the prefrontal cortex, particularly in the orbital, prelimbic, cingulate and rostral agranular portions. In addition, discrete groups of Drd4 -EGFP labelled neurons were observed in the anterior olfactory nucleus, ventral pallidum, and lateral parabrachial nucleus. EGFP was not detected in the striatum, hippocampus or midbrain as described using other techniques. Given the fine specificity of EGFP expression in BAC transgenic mice and the high sensitivity of the EGFP antibody used in this study, our results indicate that Drd4 expression in the adult mouse brain is limited to a more restricted number of areas than previously reported. Its leading expression in the prefrontal cortex supports the importance of the D4R in complex behaviours depending on cortical dopamine (DA) transmission and its possible role in the etiopathophysiology of ADHD. [source] Chronic nicotine treatment changes the axonal distribution of 68 kDa neurofilaments in the rat ventral tegmental areaEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 5 2002Andrea Sbarbati Abstract Region-specific decreases of neurofilament proteins (NF) were described in the ventral tegmental area (VTA) of rats treated chronically with morphine, cocaine or alcohol. In a previous study, we demonstrated that NF levels were also changed in the VTA after chronic treatment with nicotine. The aim of this study was to clarify the submicroscopic basis of decreased immunoreactivity for NF-68, NF-160 and NF-200, as determined by using NR4, BF10 and RT97 antibodies, respectively. Microdensitometric analysis of brain sections showed that immunoreactivity for all NF was reduced in the VTA of animals exposed chronically to nicotine (0.4 mg/kg per day, 6 days of treatment), when compared to rats exposed to saline. Reduction in immunoreactivity was significant for NF-68 (P < 0.05), NF-160 (P < 0.01) and NF-200 (P < 0.05), showing a relative reduction of 34%, 42% and 38%, respectively, when compared to saline-treated rats. No difference was observed for any of the NF under study when immunoreactivity measurements in the substantia nigra were compared. Ultrastructural analysis was applied to evaluate changes in NF-68, NF-160 and NF-200 immunoreactivity in regions of the VTA that contain dopaminergic neurons following chronic nicotine treatment. At the electron microscopic level, no degenerative changes were found in neurons or glial cells of the VTA. With ultrastructural immunohistochemistry, evaluation of the homogeneity parameter of NF distribution showed a loss of homogeneity for NF-68 linked to the nicotine treatment. In areas in which NF organization appeared well preserved, analysis of the numerical density of NF revealed no significant difference for NF-68 (897/µm2 vs. 990/µm2), NF-160 (970/µm2 vs. 820/µm2) and NF-200 (1107/µm2 vs. 905/µm2) in nicotine-treated rats when compared to saline-treated rats. These results confirm that nicotine shares the same properties with cocaine and morphine in reducing NF in the VTA, a key brain structure of the rewards system, and that chronic nicotine treatment changes the axonal distribution of 68 kDa neurofilaments in the rat VTA. [source] RCAN1-1L is overexpressed in neurons of Alzheimer's disease patientsFEBS JOURNAL, Issue 7 2007Cathryn D. Harris At least two different isoforms of RCAN1 mRNA are expressed in neuronal cells in normal human brain. Although RCAN1 mRNA is elevated in brain regions affected by Alzheimer's disease, it is not known whether the disease affects neuronal RCAN1, or if other cell types (e.g. astrocytes or microglia) are affected. It is also unknown how many protein isoforms are expressed in human brain and whether RCAN1 protein is overexpressed in Alzheimer's disease. We explored the expression of both RCAN1-1 and RCAN1-4 mRNA isoforms in various cell types in normal and Alzheimer's disease postmortem samples, using the combined technique of immunohistochemistry and in situ hybridization. We found that both exon 1 and exon 4 are predominantly expressed in neuronal cells, and no significant expression of either of the exons was observed in astocytes or microglial cells. This was true in both normal and Alzheimer's disease brain sections. We also demonstrate that RCAN1-1 mRNA levels are approximately two-fold higher in neurons from Alzheimer's disease patients versus non-Alzheimer's disease controls. Using western blotting, we now show that there are three RCAN1 protein isoforms expressed in human brain: RCAN1-1L, RCAN1-1S, and RCAN1-4. We have determined that RCAN1-1L is expressed at twice the level of RCAN1-4, and that there is very minor expression of RCAN1-1S. We also found that the RCAN1-1L protein is overexpressed in Alzheimer's disease patients, whereas RCAN1-4 is not. From these results, we conclude that RCAN1-1 may play a role in Alzheimer's disease, whereas RCAN1-4 may serve another purpose. [source] Transplanted astrocytes internalize deposited ,-amyloid peptides in a transgenic mouse model of Alzheimer's diseaseGLIA, Issue 2 2008Rea Pihlaja Abstract Alzheimer's disease (AD) is one of the most devastating neurodegenerative disorders. The neuropathological hallmarks include extracellular senile plaques consisting of deposited ,-amyloid (A,) peptides and intraneuronal neurofibrillary tangles. Neuroinflammation and activation of astrocytes are also well-established features of AD neuropathology; however, the relationships between astrocytes and A, deposition remain unclear. Previous studies have shown that adult mouse astrocytes internalize and degrade A, deposits in brain sections prepared from human amyloid precursor protein (APP) transgenic mice. In the present study, we demonstrate that cultured adult, but not neonatal mouse astrocytes, respond morphologically and degrade A, deposits present in human AD brain. We also transplanted astrocytes isolated from enhanced green fluorescent protein expressing adult and neonatal mice into the hippocampi of human A, plaque-bearing transgenic APPSwe+PS1dE9 (APdE9) mice and their wild-type littermates and followed the migration and localization of these astrocytes by confocal microscopy upto 7 days after transplantation. Posttransplantation the astrocytes localized as aggregates or thin strings of many cells within the hippocampi of APdE9 and wild-type mice and showed limited migration from the injection site. Interestingly, most of the transplanted astrocytes were found near A, deposits in the hippocampi of APdE9 mice. In contrast to findings in ex vivo degradation assay, confocal microscopy revealed that both adult and neonatal transplanted astrocytes internalized human A, immunoreactive material in vivo. These results support the role of astrocytes as active A, clearing cells in the CNS that may have important implications for future development of therapeutic strategies for AD. © 2007 Wiley-Liss, Inc. [source] Postnatal neurogenesis in the dentate gyrus of the guinea pigHIPPOCAMPUS, Issue 3 2005Sandra Guidi Abstract In all species examined, the dentate gyrus develops over an extended period that begins during gestation and continues up to adulthood. The aim of this study was to investigate the pattern of postnatal cell production in the dentate gyrus of the guinea pig, a rodent whose brain development has features more closely resembling the human condition than the most commonly used rodents (rat and mouse). Animals of different postnatal (P) ages received one or multiple injections of bromodeoxyuridine (BrdU), and the number of labeled cells in the dentate gyrus was counted after time intervals of 24 h or longer. The total granule cell number and the volume of the granule cell layer were evaluated in Nissl-stained brain sections from P1 and P30 animals. P1,P5 animals were treated with MK-801 to analyze the effect of NMDA receptor blockade on cell proliferation. Cell production occurred at a high rate (9,000,13,000 labeled cells 24 h after one injection) from P1 to P20, with a peak at 3,6 days of age, and then slowly declined from P20 to P30. The production of new cells continued in adult animals, although at a much-reduced rate (400 cells 24 h after one injection). About 20% of the labeled cells survived after a 17-day period and most (60%) of these cells had a neuronal phenotype. The total number of granule cells increased over the first postnatal month; in 30-day-old animals, it was 20% greater than in 1-day-old animals. Administration of MK-801 to P1,P5 animals caused an increase in cell proliferation restricted to the dorsal dentate gyrus. The present data show that, although the guinea pig dentate gyrus develops largely before birth, the production of new neurons continues at a high rate during the first postnatal month, leading to a considerable increase in cell number. This developmental pattern, resembling the human and nonhuman primate condition, may make the guinea pig a useful rodent model in developmental studies on dentate gyrus neurogenesis. © 2004 Wiley-Liss, Inc. [source] Effects of estrogen and progesterone treatment on rat hippocampal NMDA receptors: Relationship to Morris water maze performanceJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 4 2004Nahid K. El-Bakri Abstract Estrogen modulates NMDA receptors function in the brain. It increases both dendritic spine density and synapse number in the hippocampus, an effect that can be blocked by NMDA antagonist. In this study, we investigated the effect of 17,-estradiol and progesterone treatment on NMDA receptors in ovariectomized rats. Two different doses were used for 10 weeks. Receptor autoradiography was done on brain sections using [3H] MK-801 as a ligand. Our results showed a significant increase in [3H] MK-801 binding in the dentate gyrus, CA3 and CA4 areas of the hippocampus of ovariectomized compared to sham operated rats. In addition, we observed similar changes in CA1. 17,-estradiol treatment in both doses reduced the binding back to the normal level while progesterone treatment did not show any effect. Spatial reference memory was tested on Morris water maze task. Ovariectomy severely impaired spatial reference memory. Estradiol but not progesterone treatment significantly improved the memory performance of the ovariectomized rats. Low dose treatment showed better learning than high dose estrogen treatment. The decrease in the antagonist sites by estradiol treatment could result in an increase in the sensitivity of the hippocampus to the excitatory stimulation by glutamate system and hence the effect of estradiol on learning and memory. The changes of NMDA receptors in the hippocampus support the concept that estrogen-enhancing effect on spatial reference memory could be through the enhancing of NMDA function. [source] Heparanase mechanisms of melanoma metastasis to the brain: Development and use of a brain slice modelJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2006Brian P. Murry Abstract Heparanase (HPSE-1) is an endo-,- D -glucuronidase that cleaves heparan sulfate (HS) chains of proteoglycans (HSPG), and its expression has been associated with increased cell growth, invasion, and angiogenesis of tumors as well as with embryogenesis and tissue development. Since metastatic cancer cells express HPSE-1, we have developed an orthotopic brain slice model to study HPSE-1 involvement in brain-metastatic melanoma. This model allows for the characterization of tumor cell invasion at both quantitative and qualitative levels. Brain-metastatic melanoma cells (B16B15b) showed augmenting levels of HPSE-1 protein expression in a time-dependent manner. Secondly, B16B15b cells pre-treated with HPSE-1 showed a significant increase in the number of cells that invaded into the brain tissue. Finally, HPSE-1 exposure-augmented invasion depth in brain sections by brain-metastatic melanoma cells. We concluded that applying this brain slice model can be beneficial to investigate HPSE-1- related in vivo modalities in brain-metastatic melanoma and brain invasion in general. These results also further emphasize the potential relevance of using this model to design therapies for controlling this type of cancer by blocking HPSE-1 functionality. © 2005 Wiley-Liss, Inc. [source] Radioiodinated clioquinol as a biomarker for ,-amyloid: Zn2+ complexes in Alzheimer's diseaseAGING CELL, Issue 1 2006Carlos Opazo Summary Neocortical ,-amyloid (A,) aggregates in Alzheimer's disease (AD) are enriched in transition metals that mediate assembly. Clioquinol (CQ) targets metal interaction with A, and inhibits amyloid pathology in transgenic mice. Here, we investigated the binding properties of radioiodinated CQ ([125I]CQ) to different in vitro and in vivo Alzheimer models. We observed saturable binding of [125I]CQ to synthetic A, precipitated by Zn2+ (Kd = 0.45 and 1.40 nm for A,1-42 and A,1-40, respectively), which was fully displaced by free Zn2+, Cu2+, the chelator DTPA (diethylene triamine pentaacetic acid) and partially by Congo red. Sucrose density gradient of post-mortem AD brain indicated that [125I]CQ concentrated in a fraction enriched for both A, and Zn, which was modulated by exogenous addition of Zn2+ or DTPA. APP transgenic (Tg2576) mice injected with [125I]CQ exhibited higher brain retention of tracer compared to non-Tg mice. Autoradiography of brain sections of these animals confirmed selective [125I]CQ enrichment in the neocortex. Histologically, both thioflavine-S (ThS)-positive and negative structures were labeled by [125I]CQ. A pilot SPECT study of [123I]CQ showed limited uptake of the tracer into the brain, which did however, appear to be more rapid in AD patients compared to age-matched controls. These data support metallated A, species as the neuropharmacological target of CQ and indicate that this drug class may have potential as in vivo imaging agents for Alzheimer neuropathology. [source] Matrix-assisted laser desorption/ionization tissue profiling of secretoneurin in the nucleus accumbens shell from cocaine-sensitized ratsJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 1 2010Joachim D. Uys Abstract Proteins in the nucleus accumbens mediate many cocaine-induced behaviors. In an effort to measure changes in nucleus accumbens protein expression as potential biomarkers for addiction, coronal tissue sections were obtained from rats that developed behavioral sensitization after daily administration of cocaine, or from daily saline-treated controls. The tissue sections were subjected to matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) profiling and tissue imaging. For profiling experiments, brain sections were manually spotted with matrix over the nucleus accumbens, a brain region known to regulate cocaine sensitization. Summed mass spectra (10 000 laser shots, grid) were acquired and spectra were aligned to reference peaks. Using bioinformatics tools, eight spectral features were found to be altered by cocaine treatment. Based on additional sequencing experiments with MALDI tandem MS and database searches of measured masses, secretoneurin (m/z 3653) was identified as having an increased expression. In addition, the distribution of m/z 3653 in the nucleus accumbens was determined by MALDI tissue imaging, and the increased expression of its precursor protein, secretogranin II, was verified by immunoblotting. Copyright © 2009 John Wiley & Sons, Ltd. [source] Human brain aminopeptidase A: biochemical properties and distribution in brain nucleiJOURNAL OF NEUROCHEMISTRY, Issue 1 2008Nadia De Mota Abstract Aminopeptidase A (APA) generated brain angiotensin III, one of the main effector peptides of the brain renin angiotensin system, exerting a tonic stimulatory effect on the control of blood pressure in hypertensive rats. The distribution of APA in human brain has not been yet studied. We first biochemically characterized human brain APA (apparent molecular mass of 165 and 130 kDa) and we showed that the human enzyme exhibited similar enzymatic characteristics to recombinant mouse APA. Both enzymes had similar sensitivity to Ca2+. Kinetic studies showed that the Km (190 ,mol/L) of the human enzyme for the synthetic substrate- l -glutamyl-,-naphthylamide was close from that of the mouse enzyme (256 ,mol/L). Moreover, various classes of inhibitors including the specific and selective APA inhibitor, (S)-3-amino-4-mercapto-butyl sulfonic acid, had similar inhibitory potencies toward both enzymes. Using (S)-3-amino-4-mercapto-butyl sulfonic acid, we then specifically measured the activity of APA in 40 microdissected areas of the adult human brain. Significant heterogeneity was found in the activity of APA in the various analyzed regions. The highest activity was measured in the choroids plexus and the pineal gland. High activity was also detected in the dorsomedial medulla oblongata, in the septum, the prefrontal cortex, the olfactory bulb, the nucleus accumbens, and the hypothalamus, especially in the paraventricular and supraoptic nuclei. Immunostaining of human brain sections at the level of the medulla oblongata strengthened these data, showing for the first time a high density of immunoreactive neuronal cell bodies and fibers in the motor hypoglossal nucleus, the dorsal motor nucleus of the vagus, the nucleus of the solitary tract, the Roller nucleus, the ambiguus nucleus, the inferior olivary complex, and in the external cuneate nucleus. APA immunoreactivity was also visualized in vessels and capillaries in the dorsal motor nucleus of the vagus and the inferior olivary complex. The presence of APA in several human brain nuclei sensitive to angiotensins and involved in blood pressure regulation suggests that APA in humans is an integral component of the brain renin angiotensin system and strengthens the idea that APA inhibitors could be clinically tested as an additional therapy for the treatment of certain forms of hypertension. [source] Induction of Oxidative DNA Damage in the Peri-Infarct Region After Permanent Focal Cerebral IschemiaJOURNAL OF NEUROCHEMISTRY, Issue 4 2000Tetsuya Nagayama Abstract: To address the role of oxidative DNA damage in focal cerebral ischemia lacking reperfusion, we investigated DNA base and strand damage in a rat model of permanent middle cerebral artery occlusion (MCAO). Contents of 8-hydroxyl-2,-deoxyguanosine (8-OHdG) and apurinic/apyrimidinic abasic sites (AP sites), hallmarks of oxidative DNA damage, were quantitatively measured in nuclear DNA extracts from brains obtained 4-72 h after MCAO. DNA single- and double-strand breaks were detected on coronal brain sections using in situ DNA polymerase I-mediated biotin-dATP nick-translation (PANT) and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), respectively. Levels of 8-OHdG and AP sites were markedly elevated 16-72 h following MCAO in the frontal cortex, representing the peri-infarct region, but levels did not significantly change within the ischemic core regions of the caudateputamen and parietal cortex. PANT- and TUNEL-positive cells began to be detectable 4-8 h following MCAO in the caudate-putamen and parietal cortex and reached maximal levels at 72 h. PANT- and TUNEL-positive cells were also detected 16-72 h after MCAO in the lateral frontal cortex within the infarct border, where many cells also showed colocalization of DNA single-strand breaks and DNA fragmentation. In contrast, levels of PANT-positive cells alone were transiently increased (16 h after MCAO) in the medial frontal cortex, an area distant from the infarct zone. These data suggest that within peri-infarct brain regions, oxidative injury to nuclear DNA in the form of base and strand damage may be a significant and contributory cause of secondary expansion of brain damage following permanent focal ischemia. [source] Distinct pattern of microglial response, cyclooxygenase-2, and inducible nitric oxide synthase expression in the aged rat brain after excitotoxic damageJOURNAL OF NEUROSCIENCE RESEARCH, Issue 14 2008O. Campuzano Abstract Microglial and inflammatory responses to acute damage in aging are still poorly understood, although the aged brain responds differently to injury, showing poor lesion outcome. In this study, excitotoxicity was induced by intrastriatal injection of N-methyl-D-aspartate in adult (3,4 months) and aged (22,24 months) rats. Cryostat brain sections were processed for the analysis of microglial response by lectin histochemistry and cyclooxygenase 2 (COX2) and inducible nitric oxide synthase (iNOS) expression by immunohistochemistry and confocal analysis. Aged injured animals showed more widespread area of microglial response at 12 hr postlesion (hpl) and greater microglia/macrophage density at 3 days postlesion (dpl). However, aged reactive microglia showed prevalence of ramified morphologies and fewer amoeboid/round forms. Aged injured animals presented a diminished area of COX2 expression, but a significantly larger density of COX2+ cells, with higher numbers of COX2+ neurons during the first 24 hpl and COX2+ microglia/macrophages later. In contrast, the amount of COX2+ neutrophils was diminished in the aged. iNOS was more rapidly induced in the aged injured striatum, with higher cell density at 12 hpl, when expression was mainly neuronal. From 1 dpl, both the iNOS+ area and the density of iNOS+ cells were reduced in the aged, with lower numbers of iNOS+ neurons, microglia/macrophages, neutrophils, and astrocytes. In conclusion, excitotoxic damage in aging induces a distinct pattern of microglia/macrophage response and expression of inflammatory enzymes, which may account for the changes in lesion outcome in the aged, and highlight the importance of using aged animals for the study of acute age-related insults. © 2008 Wiley-Liss, Inc. [source] Neuroadaptations of Cdk5 in Cholinergic Interneurons of the Nucleus Accumbens and Prefrontal Cortex of Inbred Alcohol-preferring Rats Following Voluntary Alcohol DrinkingALCOHOLISM, Issue 8 2006Marguerite Charlotte Camp Background: Neurobiological studies have identified brain areas and related molecular mechanisms involved in alcohol abuse and dependence. Specific cell types in these brain areas and their role in alcohol-related behaviors, however, have not yet been identified. This study examined the involvement of cholinergic cells in inbred alcohol-preferring rats following 1 month of alcohol drinking. Cyclin-dependent kinase 5 (Cdk5) immunoreactivity (IR), a marker of neuronal plasticity, was examined in cholinergic neurons of the nucleus accumbens (NuAcc) and prefrontal cortex (PFC) and other brain areas implicated in alcohol drinking, using dual immunocytochemical (ICC) procedures. Single Cdk5 IR was also examined in several brain areas implicated in alcohol drinking. Methods: The experimental group self-administered alcohol using a 2-bottle-choice test paradigm with unlimited access to 10% (v/v) alcohol and water for 23 h/d for 1 month. An average of 6 g/kg alcohol was consumed daily. Control animals received identical treatment, except that both bottles contained water. Rats were perfused and brain sections were processed for ICC procedures. Results: Alcohol drinking resulted in a 51% increase in Cdk5 IR cholinergic interneurons in the shell NuAcc, while in the PFC there was a 51% decrease in the percent of Cdk5 IR cholinergic interneurons in the infralimbic region and a 46% decrease in Cdk5 IR cholinergic interneurons in the prelimbic region. Additionally, single Cdk5 IR revealed a 42% increase in the central nucleus of the amygdala (CNA). Conclusions: This study identified Cdk5 neuroadaptation in cholinergic interneurons of the NuAcc and PFC and in other neurons of the CNA following 1 month of alcohol drinking. These findings contribute to our understanding of the cellular and molecular basis of alcohol drinking and toward the development of improved region and cell-specific pharmacotherapeutic and behavioral treatment programs for alcohol abuse and alcoholism. [source] Chronic Ethanol-Induced Subtype- and Subregion-Specific Decrease in the mRNA Expression of Metabotropic Glutamate Receptors in Rat HippocampusALCOHOLISM, Issue 9 2004Agnes Simonyi Background: Chronic ethanol consumption is known to induce adaptive changes in the hippocampal glutamatergic transmission and alter NMDA receptor binding and subunit expression. Metabotropic glutamate (mGlu) receptors have been shown to function as modulators of neuronal excitability and can fine tune glutamatergic transmission. This study was aimed to determine whether chronic ethanol treatment could change the messenger RNA (mRNA) expression of mGlu receptors in the hippocampus. Methods: Male Sprague Dawley® rats were fed a Lieber-DeCarli liquid diet with 5% (w/v) ethanol or isocaloric amount of maltose for 2 months. Quantitative in situ hybridization was carried out using coronal brain sections through the hippocampus. Results: The results revealed decreases in mRNA expression of several mGlu receptors in different subregions of the hippocampus. In the dentate gyrus, mGlu3 and mGlu5 receptor mRNA levels were significantly lower in the ethanol-treated rats than in the control rats. In the CA3 region, the mRNA expression of mGlu1, mGlu5, and mGlu7 receptors showed substantial decreases after ethanol exposure. The mGlu7 receptor mRNA levels were also declined in the CA1 region and the polymorph layer of the dentate gyrus. No changes were found in mRNA expression of mGlu2, mGlu4, and mGlu8 receptors. Conclusions: Considering the involvement of hippocampal mGlu receptors in learning and memory processes as well as in neurotoxicity and seizure production, the reduced expression of these receptors might contribute to ethanol withdrawal-induced seizures and also may play a role in cognitive deficits and brain damage caused by long-term ethanol consumption. [source] Grape Polyphenols Inhibit Chronic Ethanol-Induced COX-2 mRNA Expression in Rat BrainALCOHOLISM, Issue 3 2002Agnes Simonyi Background: Chronic ethanol has been shown to increase oxidative stress leading to neurodegenerative changes in the brain. Oxidative stress may up-regulate extracellular signal regulated kinases (ERK1/2) and, subsequently, the arachidonic acid cascade mediated by phospholipase A2 (PLA2) and cyclooxygenase (COX-2). Our earlier study showed that grape polyphenols (GP) could ameliorate oxidative damage to synaptic membrane proteins due to chronic ethanol treatment. This study was aimed at examining the effects of GP on mRNA expression of ERK1/2, cytosolic PLA2 (cPLA2), and COX-2 in different brain regions after chronic ethanol treatment. Methods: Male Sprague-Dawley rats were fed a Lieber-DeCarli liquid diet with ethanol or isocaloric amount of maltose, with or without GP for 2 months. In situ hybridization was carried out using coronal brain sections through the hippocampus. Results: Quantitative in situ hybridization showed no changes in ERK1 and cPLA2 mRNA levels in cortical areas and hippocampus after ethanol and/or GP administration. However, a decrease in ERK2 and an increase in COX-2 mRNA level was found in the hippocampus of ethanol-treated animals. GP completely inhibited the increase in COX-2 due to ethanol treatment. Conclusion: Increase in COX-2 expression may be an underlying mechanism for the increase in oxidative stress induced by chronic ethanol administration. Dietary supplementation of GP may have a beneficial role in inhibiting certain alcohol effects. [source] Plasmodium falciparum- infected erythrocytes induce tissue factor expression in endothelial cells and support the assembly of multimolecular coagulation complexesJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 1 2007I. M. B. FRANCISCHETTI Summary.,Background:,Plasmodium falciparum malaria infects 300,500 million people every year, causing 1,2 million deaths annually. Evidence of a coagulation disorder, activation of endothelial cells (EC) and increase in inflammatory cytokines are often present in malaria. Objectives:,We have asked whether interaction of parasitized red blood cells (pRBC) with EC induces tissue factor (TF) expression in vitro and in vivo. The role of phosphatidylserine-containing pRBC to support the assembly of blood coagulation complexes was also investigated. Results:,We demonstrate that mature forms of pRBC induce functional expression of TF by EC in vitro with productive assembly of the extrinsic Xnase complex and initiation of the coagulation cascade. Late-stage pRBC also support the prothrombinase and intrinsic Xnase complex formation in vitro, and may function as activated platelets in the amplification phase of the blood coagulation. Notably, post-mortem brain sections obtained from P. falciparum -infected children who died from cerebral malaria and other causes display a consistent staining for TF in the EC. Conclusions:,These findings place TF expression by endothelium and the amplification of the coagulation cascade by pRBC and/or activated platelets as potentially critical steps in the pathogenesis of malaria. Furthermore, it may allow investigators to test other therapeutic alternatives targeting TF or modulators of EC function in the treatment of malaria and/or its complications. [source] Visualization of ,-amyloid plaques in a transgenic mouse model of Alzheimer's disease using MR microscopy without contrast reagentsMAGNETIC RESONANCE IN MEDICINE, Issue 3 2004Sang-Pil Lee Abstract The visualization of ,-amyloid plaque deposition in brain, a key feature of Alzheimer's disease (AD), is important for the evaluation of disease progression and the efficacy of therapeutic interventions. In this study, ,-amyloid plaques in the PS/APP transgenic mouse brain, a model of human AD pathology, were detected using MR microscopy without contrast reagents. ,-Amyloid plaques were clearly visible in the cortex, thalamus, and hippocampus of fixed brains of PS/APP mice. The distribution of plaques identified by MRI was in excellent agreement with those found in the immunohistological analysis of the same brain sections. It was also demonstrated that image contrast for ,-amyloid plaques was present in freshly excised nonfixed brains. Furthermore, the detection of ,-amyloid plaques was achieved with a scan time as short as 2 hr, approaching the scan time considered reasonable for in vivo imaging. Magn Reson Med 52:538,544, 2004. © 2004 Wiley-Liss, Inc. [source] An automatic integrated approach for stained neuron detection in studying neuron migrationMICROSCOPY RESEARCH AND TECHNIQUE, Issue 2 2010Yue Huang Abstract Neurons that come to populate the six-layered cerebral cortex are born deep within the developing brain in the surface of the embryonic cerebral ventricles. It is very important to detect these neurons for studying histogenesis of the brain and abnormal migration that had been linked to cognitive deficits, mental retardation, and motor disorders. The visualization of labeled cells in brain sections was performed by immunocytochemical examination and its image data were documented to microscopic pictures. Based on the fact, automatic accurate neurons labeling is prerequisite instead of time-consuming manual labeling. In this article, a fully automated image processing approach is proposed to detect all the stained neurons in microscopic images. First of all, dark stained neurons are achieved by thresholding in blue channel of image. And then a modified fuzzy c-means clustering method, called alternative fuzzy c-means is applied to achieve higher classification accuracy in extracting constraint factor. Finally, watershed based on gradient vector flow is employed to the constraint factor image to segment all the neurons, including clustered neurons. The results demonstrate that the proposed method can be a useful tool in neuron image analysis. Microsc. Res. Tech. 2010. © 2009 Wiley-Liss, Inc. [source] Polarized light imaging of white matter architectureMICROSCOPY RESEARCH AND TECHNIQUE, Issue 10 2007Luiza Larsen Abstract Polarized light imaging (PLI) is a method to image fiber orientation in gross histological brain sections based on the birefringent properties of the myelin sheaths. The method uses the transmission of polarized light to quantitatively estimate the fiber orientation and inclination angles at every point of the imaged section. Multiple sections can be assembled into a 3D volume, from which the 3D extent of fiber tracts can be extracted. This article describes the physical principles of PLI and describes two major applications of the method: the imaging of white matter orientation of the rat brain and the generation of fiber orientation maps of the human brain in white and gray matter. The strengths and weaknesses of the method are set out. Microsc. Res. Tech., 2007. © 2007 Wiley-Liss, Inc. [source] Imaging of uranium on rat brain sections using laser ablation inductively coupled plasma mass spectrometry: a new tool for the study of critical substructures affined to heavy metals in tissuesRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 18 2008J. Sabine Becker The specific toxicity of trace metals and compounds largely depends on their bioavailability in different organs or compartments of the organism considered. Imaging mass spectrometry (IMS) using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) with a spatial resolution in the 100,µm range was developed and employed to study heavy metal distribution in brain tissues for toxicological screening. Rat brain post-mortem tissues were stained in an aqueous solution of either uranium or neodymium (metal concentration 100,µg,g,1) for 3,h. The incubation of heavy metal in thin slices of brain tissue is followed by an imaging mass spectrometric LA-ICP-MS technique. Stained rat brain tissue (thickness 30,µm) were scanned with a focused laser beam (wavelength 266,nm, diameter of laser crater 100,µm and laser power density 3,×,109,W,cm,2). The ion intensities of 235U+, 238U+, 145Nd+ and 146Nd+ were measured by LA-ICP-MS within the ablated area. For quantification purposes, matrix-matched laboratory standards were prepared by dosing each analyte to the pieces of homogenized brain tissue. Imaging LA-ICP-MS allows structures of interest to be identified and the relevant dose range to be estimated. Copyright © 2008 John Wiley & Sons, Ltd. [source] Development of nitrergic neurons in the nervous system of the locust embryoTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 8 2010Michael Stern We followed the development of the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) system during locust embryogenesis in whole mount nervous systems and brain sections by using various cytochemical techniques. We visualized NO-sensitive neurons by cGMP immunofluorescence after incubation with an NO donor in the presence of the soluble guanylyl cyclase (sGC) activator YC-1 and the phosphodiesterase-inhibitor isobutyl-methyl-xanthine (IBMX). Central nervous system (CNS) cells respond to NO as early as 38% embryogenesis. By using the NADPH-diaphorase technique, we identified somata and neurites of possible NO-synthesizing cells in the CNS. The first NADPH-diaphorase-positive cell bodies appear around 40% embryogenesis in the brain and at 47% in the ventral nerve cord. The number of positive cells reaches the full complement of adult cells at 80%. In the brain, some structures, e.g., the mushroom bodies acquire NADPH-diaphorase staining only postembryonically. Immunolocalization of L-citrulline confirmed the presence of NOS in NADPH-diaphorase-stained neurons and, in addition, indicated enzymatic activity in vivo. In whole mount ventral nerve cords, citrulline immunolabeling was present in varying subsets of NADPH-diaphorase-positive cells, but staining was very variable and often weak. However, in a regeneration paradigm in which one of the two connectives between ganglia had been crushed, strong, reliable staining was observed as early as 60% embryogenesis. Thus, citrulline immunolabeling appears to reflect specific activity of NOS. However, in younger embryos, NOS may not always be constitutively active or may be so at a very low level, below the citrulline antibody detection threshold. For the CNS, histochemical markers for NOS do not provide conclusive evidence for a developmental role of this enzyme. J. Comp. Neurol. 518:1157,1175, 2010. © 2010 Wiley-Liss, Inc. [source] Development of nitrergic neurons in the nervous system of the locust embryoTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 8 2010Michael Stern Abstract We followed the development of the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) system during locust embryogenesis in whole mount nervous systems and brain sections by using various cytochemical techniques. We visualized NO-sensitive neurons by cGMP immunofluorescence after incubation with an NO donor in the presence of the soluble guanylyl cyclase (sGC) activator YC-1 and the phosphodiesterase-inhibitor isobutyl-methyl-xanthine (IBMX). Central nervous system (CNS) cells respond to NO as early as 38% embryogenesis. By using the NADPH-diaphorase technique, we identified somata and neurites of possible NO-synthesizing cells in the CNS. The first NADPH-diaphorase-positive cell bodies appear around 40% embryogenesis in the brain and at 47% in the ventral nerve cord. The number of positive cells reaches the full complement of adult cells at 80%. In the brain, some structures, e.g., the mushroom bodies acquire NADPH-diaphorase staining only postembryonically. Immunolocalization of L-citrulline confirmed the presence of NOS in NADPH-diaphorase-stained neurons and, in addition, indicated enzymatic activity in vivo. In whole mount ventral nerve cords, citrulline immunolabeling was present in varying subsets of NADPH-diaphorase-positive cells, but staining was very variable and often weak. However, in a regeneration paradigm in which one of the two connectives between ganglia had been crushed, strong, reliable staining was observed as early as 60% embryogenesis. Thus, citrulline immunolabeling appears to reflect specific activity of NOS. However, in younger embryos, NOS may not always be constitutively active or may be so at a very low level, below the citrulline antibody detection threshold. For the CNS, histochemical markers for NOS do not provide conclusive evidence for a developmental role of this enzyme. J. Comp. Neurol. 518:1157,1175, 2010. © 2009 Wiley-Liss, Inc. [source] Cellular and molecular tunnels surrounding the forebrain commissures of human fetusesTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 4 2005Roberto Lent Abstract Glial cells and extracellular matrix (ECM) molecules surround developing fiber tracts and are implicated in axonal pathfinding. These and other molecules are produced by these strategically located glial cells and have been shown to influence axonal growth across the midline in rodents. We searched for similar cellular and molecular structures surrounding the telencephalic commissures of fetal human brains. Paraffin-embedded brain sections were immunostained for glial fibrillary acidic protein (GFAP) and vimentin (VN) to identify glial cells; for microtubule-associated protein-2 (MAP-2) and neuronal nuclear protein (NeuN) to document neurons; for neurofilament (NF) to identify axons; and for chondroitin sulfate (CS), tenascin (TN), and fibronectin (FN) to show the ECM. As in rodents, three cellular clusters surrounding the corpus callosum were identified by their expression of GFAP and VN (but not MAP-2 or NeuN) from 13 to at least 18 weeks postovulation (wpo): the glial wedge, the glia of the indusium griseum, and the midline sling. CS and TN (but not FN) were expressed pericellularly in these cell groups. The anterior commissure was surrounded by a GFAP+/VN+ glial tunnel from 12 wpo, with TN expression seen between the GFAP+ cell bodies. The fimbria showed GFAP+/VN+ cells at its lateral and medial borders from 12 wpo, with pericellular expression of CS. The fornix showed GFAP+ cells somewhat later (16 wpo). Because these structures are similar to those described for rodents, we concluded that the axon guiding mechanisms postulated for commissural formation in nonhuman mammals may also be operant in the developing human brain. J. Comp. Neurol. 483:375,382, 2005. © 2005 Wiley-Liss, Inc. [source] Microemboli may link spreading depression, migraine aura, and patent foramen ovaleANNALS OF NEUROLOGY, Issue 2 2010Ala Nozari MD Objective Patent foramen ovale and pulmonary arteriovenous shunts are associated with serious complications such as cerebral emboli, stroke, and migraine with aura. The pathophysiological mechanisms that link these conditions are unknown. We aimed to establish a mechanism linking microembolization to migraine aura in an experimental animal model. Methods We introduced particulate or air microemboli into the carotid circulation in mice to determine whether transient microvascular occlusion, insufficient to cause infarcts, triggered cortical spreading depression (CSD), a propagating slow depolarization that underlies migraine aura. Results Air microemboli reliably triggered CSD without causing infarction. Polystyrene microspheres (10,m) or cholesterol crystals (<70,m) triggered CSD in 16 of 28 mice, with 60% of the mice (40% of those with CSD) showing no infarcts or inflammation on detailed histological analysis of serial brain sections. No evidence of injury was detected on magnetic resonance imaging examination (9.4T; T2 weighted) in 14 of 15 selected animals. The occurrence of CSD appeared to be related to the magnitude and duration of flow reduction, with a triggering mechanism that depended on decreased brain perfusion but not sustained tissue damage. Interpretation In a mouse model, microemboli triggered CSD, often without causing microinfarction. Paradoxical embolization then may link cardiac and extracardiac right-to-left shunts to migraine aura. If translatable to humans, a subset of migraine auras may belong to a spectrum of hypoperfusion disorders along with transient ischemic attacks and silent infarcts. ANN NEUROL 2010;67:221,229 [source] Potassium channels Kv1.3 and Kv1.5 are expressed on blood-derived dendritic cells in the central nervous systemANNALS OF NEUROLOGY, Issue 1 2006Katherine M. Mullen AB Objective Potassium (K+) channels on immune cells have gained attention recently as promising targets of therapy for immune-mediated neurological diseases such as multiple sclerosis (MS). We examined K+ channels on dendritic cells (DCs), which infiltrate the brain in MS and may impact disease course. Methods We identified K+ channels on blood-derived DCs by whole-cell patch-clamp analysis, confirmed by immunofluorescent staining. We also stained K+ channels in brain sections from MS patients and control subjects. To test functionality, we blocked Kv1.3 and Kv1.5 in stimulated DCs with pharmacological blockers or with an inducible dominant-negative Kv1.x adenovirus construct and analyzed changes in costimulatory molecule upregulation. Results Electrophysiological analysis of DCs showed an inward-rectifying K+ current early after stimulation, replaced by a mix of voltage-gated Kv1.3- and Kv1.5-like channels at later stages of maturation. Kv1.3 and Kv1.5 were also highly expressed on DCs infiltrating MS brain tissue. Of note, we found that CD83, CD80, CD86, CD40, and interleukin-12 upregulation were significantly impaired on Kv1.3 and Kv1.5 blockade. Interpretation These data support a functional role of Kv1.5 and Kv1.3 on activated human DCs and further define the mechanisms by which K+ channel blockade may act to suppress immune-mediated neurological diseases. Ann Neurol 2006 [source] Oleamide is a selective endogenous agonist of rat and human CB1 cannabinoid receptorsBRITISH JOURNAL OF PHARMACOLOGY, Issue 2 2004James D Leggett The ability of the endogenous fatty acid amide, cis -oleamide (ODA), to bind to and activate cannabinoid CB1 and CB2 receptors was investigated. ODA competitively inhibited binding of the nonselective cannabinoid agonist [3H]CP55,940 and the selective CB1 antagonist [3H]SR141716A to rat whole-brain membranes with Ki values of 1.14 ,M (0.52,2.53 ,M, Hill slope=0.80, n=6) and 2.63 ,M (0.62,11.20 ,M, Hill slope=0.92, n=4), respectively. AEA inhibited [3H]CP55,940 binding in rat whole-brain membranes with a Ki of 428 nM (346,510 nM, Hill slope=,1.33, n=3). ODA competitively inhibited [3H]CP55,940 binding in human CB1 (hCB1) cell membranes with a Ki value of 8.13 ,M (4.97,13.32 ,M, n=2). In human CB2 transfected (hCB2) HEK-293T cell membranes, 100 ,M ODA produced only a partial (42.5±7%) inhibition of [3H]CP55,940 binding. ODA stimulated [35S]GTP,S binding in a concentration-dependent manner (EC50=1.64 ,M (0.29,9.32 ,M), R2=0.99, n=4,9), with maximal stimulation of 188±9% of basal at 100 ,M. AEA stimulated [35S]GTP,S binding with an EC50 of 10.43 ,M (4.45,24.42 ,M, R2=1.00, n=3, 195±4% of basal at 300 ,M). Trans -oleamide (trans- ODA) failed to significantly stimulate [35S]GTP,S binding at concentrations up to 100 ,M. ODA (10 ,M)-stimulated [35S]GTP,S binding was reversed by the selective CB1 antagonist SR141716A (IC50=2.11 nM (0.32,13.77 nM), R2=1.00, n=6). The anatomical distribution of ODA-stimulated [35S]GTP,S binding in rat brain sections was indistinguishable from that of HU210. Increases of similar magnitude were observed due to both agonists in the striatum, cortex, hippocampus and cerebellum. ODA (10 ,M) significantly inhibited forskolin-stimulated cyclic AMP (cAMP) accumulation in mouse neuroblastoma N1E 115 cells (P=0.02, n=11). ODA-mediated inhibition was completely reversed by 1 ,M SR141716A (P<0.001, n=11) and was also reversed by pretreatment with 300 ng ml,1 pertussis toxin (P<0.001, n=6). These data demonstrate that ODA is a full cannabinoid CB1 receptor agonist. Therefore, in addition to allosteric modulation of other receptors and possible entourage effects due to fatty acid amide hydrolase inhibition, the effects of ODA may be mediated directly via the CB1 receptor. British Journal of Pharmacology (2004) 141, 253,262. doi:10.1038/sj.bjp.0705607 [source] | ||||||||||||||||