bluuebunny/crossref_metadata_2025_split huggingface dataset:
GFAP knockout mice have increased levels of GDNF that protect striatal neurons from metabolic and excitotoxic insults
Authors: Hanbury Rose , Ling Zao Dung , Wuu Joanne , Kordower Jeffrey H. 
Published: May 2003

AbstractIn response to injury and degeneration, astrocytes hypertrophy, extend processes, and increase production of glial fibrillary acidic protein (GFAP), an intermediate filament protein located within their cytoplasm. The present study tested the hypothesis that GFAP expression alters the vulnerability of neurons to excitotoxic and metabolic insult induced by 3‐nitroproprionic acid (3‐NP), an irreversible inhibitor of mitochondrial complex II activity or the excitotoxin quinolinic acid (QA). In this respect, adult GFAP knockout mice (KO) and wild‐type control mice (WT) received unilateral intrastriatal injections of 3‐NP (200 nmol/μl) or QA (100 nmol/μl) and were killed 1, 2, or 4 weeks later. Lesion volume and neuronal counts were quantified using unbiased stereologic principles. For both QA and 3‐NP lesions, a significant decrease in lesion volume and an increase in striatal projection neurons were seen in GFAP KO mice compared with WT mice. Enzyme‐linked immunoassay analysis revealed increased basal levels of glial cell derived neurotrophic factor (GDNF) relative to WT mice. In contrast, no differences were observed in the expression of ciliary neurotrophic factor or nerve growth factor. These data strongly suggest that the expression of GFAP is implicated with the production of GDNF to a degree that confers neuroprotection after an excitotoxic or metabolic insult. J. Comp. Neurol. 461:307–316, 2003. © 2003 Wiley‐Liss, Inc.
Expression of metabotropic glutamate receptors in rat meningeal and brain microvasculature and choroid plexus
Authors: Gillard Samantha E. , Tzaferis John , Tsui Ho‐Ching Tiffany , Kingston Ann E. 
Published: May 2003

AbstractThis study investigated the distribution of metabotropic glutamate receptors (mGluRs) in meningeal and parenchymal microvasculature and in choroid plexus by means of Western blot analysis and immunohistochemistry. Western blot analysis demonstrated mGluR expression in both rat and human leptomeningeal tissues. In the rat, mGluR expression was developmentally regulated, with only mGluR2/3 showing expression at the embryonic day 19 developmental stage. In contrast, mGluR1α, mGluR2/3, mGluR4a, and mGluR7 were expressed in leptomeninges from adult rats. Immunohistochemical analyses showed intense mGluR1α immunoreactivity in the pia mater and blood vessels in the subarachnoid space and in the arachnoid layer of the meninges. mGluR2/3, mGluR4a, mGluR5, and mGluR7 were also expressed in meningeal microvasculature. In addition, the parenchymal microvasculature and choroid plexus were strongly immunoreactive for mGluR1α, mGluR2/3, mGluR4a, mGluR5, and mGluR7. We used antibodies specific for phenotypic markers of microvascular and glial cells to characterize the cell type(s) immunopositive for mGluRs. Comparison of staining with anti–von Willebrand factor antibody and anti‐mGluR antibodies revealed that mGluR immunoreactivity was present in cells that surrounded the luminal surface labeled by the endothelial cell marker. In these cells, smooth muscle actin and mGluR immunoreactivity overlapped, suggesting that, in addition to endothelial cells, pericytes within the microvasculature also express mGluRs. Furthermore, expression of mGluR1α was also observed in pure pericyte cultures isolated from bovine retina. These data suggest that glutamate by means of activation of mGluRs may have a broad sphere of physiological influence in the brain which in addition to modulating synaptic transmission may also have a role in determining microvascular function and dysfunction. J. Comp. Neurol. 461:317–332, 2003. © 2003 Wiley‐Liss, Inc.
Ontogeny of ultraviolet‐sensitive cones in the retina of rainbow trout (Oncorhynchus mykiss)
Authors: Allison W. Ted , Dann Stephen G. , Vidar Helvik Jon , Bradley Clarrisa , Moyer Heather D. , Hawryshyn Craig W. 
Published: May 2003

AbstractIn order to facilitate emerging models of retinal development, we developed electroretinogram and in situ hybridization protocols to examine the ontogeny of photoreceptors in the retina of a land‐locked salmonid, the rainbow trout (Oncorhynchus mykiss). We cloned cDNA fragments corresponding to the rod opsin and each of the four cone opsin gene families, which we utilized to produce riboprobes. We established the specificity of the in situ hybridization protocol by examining subcellular signal localization and through double‐labeling experiments. We confirm the assumption that the accessory corner cones in the square mosaic are the ultraviolet wavelength‐sensitive (UVS) cone photoreceptor (i.e., they express an SWS1 opsin) and observed UVS cones throughout the retina of small trout. Larger fish have a decrease in sensitivity to short wavelength light stimuli and the distribution of UVS cones in the mature retina is limited to the dorsal‐temporal quadrant. These larger fish also possess differentiated UVS cones in the peripheral germinal zone (PGZ), including within areas peripheral to mature retina lacking UVS cones. These data are consistent with the loss of putative UVS cones from the PGZ of a migratory salmonid of another genus, and thus the disappearance of UVS cones appears to be general to the Family Salmonidae, regardless of life history strategy. The generation, differentiation, and subsequent loss of UVS cones in the smolt PGZ is a dramatic example of the supposition that the mechanisms of PGZ development recapitulate the retinal embryogenesis of that species. J. Comp. Neurol. 461:294–306, 2003. © 2003 Wiley‐Liss, Inc.
Expression of the genes GAD67 and Distal‐less‐4 in the forebrain of Xenopus laevis confirms a common pattern in tetrapods
Authors: Brox Aurora , Puelles Luis , Ferreiro Beatriz , Medina Loreta 
Published: May 2003

AbstractWe investigated whether γ‐amino butyric acidergic (GABAergic) cell populations correlate positionally with specific Dlx‐expressing histogenetic territories in an anamniote tetrapod, the frog Xenopus laevis. To that end, we cloned a fragment of Xenopus GAD67 gene (xGAD67, expressed in GABAergic neurons) and compared its expression with that of Distal‐less‐4 gene (xDll‐4, ortholog of mouse Dlx2) in the forebrain at late larval and adult stages. In Xenopus, GABAergic neurons were densely concentrated in xDll‐4–positive territories, such as the telencephalic subpallium, part of the hypothalamus, and ventral thalamus, where nearly all neurons expressed both genes. In contrast, the pallium of Xenopus generally contained dispersed neurons expressing xGAD67 or xDll‐4, which may represent local circuit neurons. As in amniotes, these pallial interneurons may have been produced in the subpallium and migrated tangentially into the pallium during development. In Xenopus, the ventral division of the classic lateral pallium contained extremely few GABAergic cells and showed only low signal of the pallial gene Emx1, suggesting that it may represent the amphibian ventral pallium, homologous to that of amniotes. At caudal forebrain levels, a number of GABAergic neurons was observed in several areas (dorsal thalamus, pretectum), but no correlation to xDll‐4 was observed there. The location of GABAergic neurons in the forebrain and their relation to the developmental regulatory genes Dll and Dlx were very similar in Xenopus and in amniotes. The close correlation in the expression of both genes in rostral forebrain regions supported the notion that Dll/Dlx are among the genes involved in the acquisition of the GABAergic phenotype. J. Comp. Neurol. 461:370–393, 2003. © 2003 Wiley‐Liss, Inc.
Characterization of the cDNA encoding a somatostatin variant in the chicken brain: Comparison of the distribution of the two somatostatin precursor mRNAs
Authors: Trabucchi Michele , Tostivint Hervé , Lihrmann Isabelle , Blähser Sabine , Vallarino Mauro , Vaudry Hubert 
Published: May 2003

AbstractAlthough the existence of two somatostatin variants (SS1 and SS2) has now been demonstrated in the brain of mammals, amphibians, and fish, only one isoform of somatostatin (SS1) has been characterized to date in the brain of birds. Here we report cloning of the cDNA encoding a 101‐amino‐acid protein (PSS2) that encompasses the somatostatin variant [Pro2]somatostatin‐14 (SS2) at its C‐terminus. Sequence analysis indicated that chicken PSS2 is more closely related to fish PSS2 than to mammalian cortistatin precursors. Northern blot analysis showed that the chicken PSS1 gene is expressed in the central nervous system (CNS) and in the pancreas, whereas the PSS2 gene is expressed only in the CNS and not in peripheral organs. In situ hybridization histochemistry revealed that, in the chicken brain, PSS1 mRNA is more widely distributed than PSS2 mRNA. In particular, PSS1 mRNA expression was found in the hippocampus, the hyperstriatum, the preoptic area, the ventricular hypothalamic nuclei, the optic tectum, and several nuclei of the mesencephalon and rhombencephalon. In contrast, the distribution of PSS2 mRNA was restricted to a few regions of the brain, including the paraolfactory lobe, the paleostriatum, and some nuclei of the mesencephalon and rhombencephalon. The fact that the PSS1 and PSS2 genes are differently expressed in the brain and in peripheral organs indicates that, in chicken, the two somatostatin variants likely exert distinct functions. In particular, the observation that PSS1 mRNA, but not PSS2 mRNA, occurs in the preoptic area and in the ventral hypothalamic nuclei suggests that, of the two somatostatin isoforms, only SS1 acts as a hypophysiotropic factor. J. Comp. Neurol. 461:441–451, 2003. © 2003 Wiley‐Liss, Inc.
Distribution of neuropeptide Y immunoreactivity in the central and peripheral nervous systems of amphioxus (Branchiostoma lanceolatum Pallas)
Authors: Castro Antonio , Manso María Jesús , Anadón Ramón 
Published: May 2003

AbstractImmunocytochemistry techniques were employed to investigate the distribution of neuropeptide Y‐like‐immunoreactive (NPY‐ir) cells and fibers in the central and peripheral nervous systems of adult amphioxus. NPY‐ir neurons of the commissural type were abundant in the brain and present but more scarce in the spinal cord. These neurons gave rise to conspicuous NPY‐ir tracts that coursed along the entire length of the nerve cord. Some fibers exhibited conspicuous Herring body‐like swellings. In the peripheral nervous system, small NPY‐ir neurons and a large number of thin, beaded NPY‐ir fibers were observed in the atrial region, indicating the involvement of this substance in visceral regulation. A few NPY‐ir fibers, possibly afferent to the spinal cord, coursed in the ventral branches of the spinal nerves of this region, whereas no NPY‐ir fibers coursed in the preoral or velar nerves or in the dorsal branches of the other spinal nerves. These results indicate that NPY is widely used as a neuroregulator/neurotransmitter in the central and peripheral nervous systems of this primitive chordate. In addition, this study demonstrates the presence of tall, thin NPY‐ir cells in the putative adenohypophyseal homologue, the Hatschek's pit organ, which is located in the roof of the preoral cavity (vestibule). J. Comp. Neurol. 461:350–361, 2003. © 2003 Wiley‐Liss, Inc.
Synaptic targets of commissural interneurons in the lumbar spinal cord of neonatal rats
Authors: Birinyi András , Viszokay Kornél , Wéber Ildikó , Kiehn Ole , Antal Miklós 
Published: May 2003

AbstractThere is strong evidence that commissural interneurons, neurons with axons that extend to the contralateral side of the spinal cord, play an important role in the coordination of left/right alternation during locomotion. In this study we investigated the projections of commissural interneurons to motor neurons and other commissural interneurons on the other side of the spinal cord in neonatal rats. To establish whether there are direct contacts between axons of commissural interneurons and motor neurons, we carried out two series of experiments. In the first experiment we injected biotinylated dextran amine (BDA) into the lateral motor column to retrogradely label commissural interneurons that may have direct projections to motor neurons. Stained neurons were recovered in the ventromedial areas of the contralateral gray matter in substantial numbers. In the second experiment BDA was injected into the ventromedial gray matter on one side of the lumbar spinal cord, whereas motor neurons were simultaneously labeled on the opposite side by applying biocytin onto the ventral roots. BDA injections into the ventromedial gray matter labeled a strong axon bundle that arose from the site of injection, crossed the midline in the ventral commissure, and extensively arborized in the contralateral ventral gray matter. Many of these axons made close appositions with dendrites and somata of motor neurons and also with commissural interneurons retrogradely labeled with BDA. The results suggest that commissural interneurons may establish monosynaptic contacts with motor neurons on the opposite side of the spinal cord. Our findings also indicate that direct reciprocal connections between commissural interneurons on the two sides of the spinal cord may also exist. J. Comp. Neurol. 461:429–440, 2003. © 2003 Wiley‐Liss, Inc.
Quantitative trait loci modulate ventricular size in the mouse brain
Authors: Zygourakis Corinna C. , Rosen Glenn D. 
Published: May 2003

AbstractCerebral ventricular size in humans varies significantly. Abnormal enlargement of the ventricles has been associated with schizophrenia, and hydrocephalus can lead to serious cognitive and motor deficiencies in humans and animals. In this study, we mapped quantitative trait loci (QTLs) modulating cerebroventricular size in mice. We hypothesized that genes underlying hydrocephalus might also modulate normal variation in ventricular size. By using digital images of mouse brain sections and stereological techniques, we estimated the volume of the combined lateral and third ventricles, as well as the volume of the entire brain, in 228 AXB and BXA recombinant inbred mice and their parent strains (A/J and C57BL/6J). Ventricle size, expressed as percentage of brain volume, is a heritable trait (h2= 0.32). We detected a major QTL controlling variance in volume on chromosome (Chr) 8 near the markersD8Mit94andD8Mit189. We also detected a strong epistatic interaction affecting ventricular volume between loci on Chr 4 (nearD4Mit237andD4Mit214) and on Chr 7 (D7Mit178andD7Mit191). These three QTLs, labeledVent8a,Vent4b, andVent7c, are close to genes that have been previously implicated in hydrocephalus. J. Comp. Neurol. 461:362–369, 2003. © 2003 Wiley‐Liss, Inc.
Abnormal cerebellar histogenesis in PEX2 Zellweger mice reflects multiple neuronal defects induced by peroxisome deficiency
Authors: Faust Phyllis L. 
Published: May 2003

AbstractThe form and circuitry of the cerebellum develops by a complex process that requires integration of afferent–target interactions between multiple neuronal populations and migratory patterns established by neuron–glial interactions. Analysis of mice lacking the PEX2 peroxisome assembly gene, in which peroxisomal function is disrupted, reveals abnormal cerebellar histogenesis due to the disturbance of multiple cellular processes within neurons. Defects in cerebellar growth and the rostro‐caudal foliation pattern reflect a reduced granule neuron population and abnormal Purkinje cell dendrite development. In granule neurons, there is increased apoptotic cell death and delayed movement from the EGL to IGL that reflects cell cycle, maturational and migrational abnormalities. The underlying Purkinje cells have stunted dendrite arbors with abnormal branching patterns, which may reflect altered inductive influences from the delayed granule neuron translocation. A delayed arborization of mutant olivary climbing fibers and their defective translocation from the perisomatic to the dendritic compartment of Purkinje cells results in numerous spines on the soma and proximal dendrites of Purkinje cells. Distal Purkinje cell dendritic spines also display abnormal morphology. These Purkinje cell dendritic abnormalities are seen in association with persistent and enlarged axonal spheroids, further indicating the presence of a degenerative process within the Purkinje cell. This PEX2−/− mouse model for the human peroxisomal biogenesis disorder Zellweger syndrome illustrates the complex interplay of abnormal developmental processes in the cerebellum and the importance of peroxisomal function for neuronal migration, proliferation, differentiation, and survival. J. Comp. Neurol. 461:394–413, 2003. © 2003 Wiley‐Liss, Inc.
Patterns of expression of neuropeptides in GABAergic nonprincipal neurons in the mouse hippocampus: Quantitative analysis with optical disector
Authors: Jinno Shozo , Kosaka Toshio 
Published: May 2003

AbstractNeuropeptides are widely distributed in the central nervous system and are considered to play important roles in the regulation of neuronal activity. This study shows the patterns of expression of four neuropeptides [neuropeptide Y (NPY), somatostatin (SOM), cholecystokinin (CCK), and vasoactive intestinal polypeptide (VIP)] in γ‐aminobutyric acid (GABA)‐ergic neurons of the mouse hippocampus, with particular reference to the areal and dorsoventral difference. First, we estimated the numerical densities (NDs) of GABAergic neurons containing these neuropeptides using the optical disector. The NDs of NPY‐ and SOM‐positive GABAergic neurons were generally higher than those of CCK‐ and VIP‐positive GABAergic neurons. In the whole area of the hippocampus, the ND of NPY‐positive GABAergic neurons showed no significant dorsoventral difference (1.90 × 103/mm3 in the dorsal level, 2.09 × 103/mm3 in the ventral level), whereas the ND of SOM‐positive GABAergic neurons was higher in the ventral level (1.44 × 103/mm3) than in the dorsal level (0.80 × 103/mm3). The ND of CCK‐positive GABAergic neurons was also higher in the ventral level (0.57 × 103/mm3) than in the dorsal level (0.33 × 103/mm3). Similarly, the ND of VIP‐positive GABAergic neurons was higher in the ventral level (0.61 × 103/mm3) than in the dorsal level (0.43 × 103/mm3). Next, we calculated the proportions of GABAergic neurons containing these neuropeptides among the total GABAergic neurons. In the whole area of the hippocampus, NPY‐, SOM‐, CCK‐, and VIP‐positive neurons accounted for about 31%, 17%, 7%, and 8% of GABAergic neurons, respectively. The present data establish a baseline for examining potential roles of GABAergic neurons in the hippocampal network activity in mice. J. Comp. Neurol. 461:333–349, 2003. © 2003 Wiley‐Liss, Inc.
Developmental change in expression and subcellular localization of two Shaker‐related potassium channel proteins (Kv1.1 and Kv1.2) in the chick tangential vestibular nucleus
Authors: Popratiloff Anastas , Giaume Christian , Peusner Kenna D. 
Published: May 2003

AbstractThe chick tangential nucleus is a major avian vestibular nucleus whose principal cells participate in two vestibular reflexes. Intracellular recordings have shown that the principal cells acquire their mature firing pattern gradually during development. At embryonic day 16 (E16), most principal cells fire a single spike, whereas shortly after hatching (H) the vast majority fire repetitively on depolarization. The transition in firing pattern was likely due in part to a downregulation of a low‐threshold, sustained, dendrotoxin‐sensitive (DTX) potassium current, IDS. Since the DTX‐sensitive potassium channel subunits Kv1.1 and Kv1.2 generate sustained currents, in the present study we applied fluorescence immunocytochemistry and confocal microscopy to characterize their developmental expression at E16, H1, and H9. At E16, both Kv1.1 and Kv1.2 staining were confined to the principal cell bodies. Immunolabeling decreased significantly for both proteins at H1, and more so by H9. Double‐labeling with a monoclonal antibody against microtubule‐associated protein 2 (MAP2) in hatchlings showed that some Kv1.1 remained as clusters within the cell body, at the base of the dendrites, and in the axon initial segment. In hatchlings, Kv1.2 staining decreased in the cell bodies and simultaneously appeared in the neuropil, colocalized with biocytin‐labeled primary vestibular fibers and vestibular “spoon” terminals. Also, double‐labeling with synaptotagmin showed that Kv1.2 colocalized with many nonvestibular terminals surrounding the principal cell bodies. These results identified developmental decreases in the staining of these two potassium channel protein subunits and changes in their subcellular localization corresponding to the downregulation of IDS defined electrophysiologically around hatching. Accordingly, both of these protein subunits could be involved in regulating excitability of the principal cells. J. Comp. Neurol. 461:466–482, 2003. © 2003 Wiley‐Liss, Inc.
Autoradiographic analysis of rat brain kinin B1 and B2 receptors: Normal distribution and alterations induced by epilepsy
Authors: Ongali Brice , Campos Maria Martha , Bregola Gianni , Rodi Donata , Regoli Domenico , Thibault Gaétan , Simonato Michele , Couture Réjean 
Published: May 2003

AbstractKindling‐induced seizures constitute an experimental model of human temporal lobe epilepsy that is associated with changes in the expression of several inflammatory proteins and/or their receptors in distinct brain regions. In the present study, alterations of kinin receptors in the brain of amygdaloid‐kindled rats were assessed by means of in vitro autoradiography, using 125I‐labeled 3‐4 hydroxyphenyl‐propionyl‐desArg9‐D‐Arg°‐[Hyp3, Thi5, D‐Tic7, Oic8]‐bradykinin (B1 receptors) and 125I‐labeled 3‐4 hydroxyphenyl‐propionyl‐D‐Arg°‐[Hyp3, Thi5, D‐Tic7, Oic8]‐bradykinin (B2 receptors) as ligands. Results demonstrate that B2 receptors are widely distributed throughout the brain of control rats. The highest densities were observed in lateral septal nucleus, median preoptic nucleus, dentate gyrus, amygdala, spinal trigeminal nucleus, mediovestibular nucleus, inferior cerebellar peduncles, and in most of cortical regions (0.81–1.4 fmol/mg tissue). In contrast, very low densities of B1 receptors were detected in all analyzed areas from control rats (0.18–0.26 fmol/mg tissue). When assessed in kindled rats, specific binding sites for B2 receptors were significantly decreased (41 to 76%) in various brain areas. Conversely, B1 receptor binding sites were markedly increased in kindled rats, especially in hippocampus (CA2 ≅ CA1 ≅ CA3), Amy and entorhinal, peririnal/piriform, and occipital cortices (152–258%). Data show for the first time that kindling‐induced epilepsy results in a significant decline of B2 receptor binding sites, accompanied by a striking increase of B1 receptor labeling in the rat brain. An altered balance between B1 and B2 receptor populations may play a pivotal role in the onset and/or maintenance of epilepsy. J. Comp. Neurol. 461:506–519, 2003. © 2003 Wiley‐Liss, Inc.