bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organization of N‐methyl‐D‐aspartate glutamate receptor gene expression in the basal ganglia of the rat
Authors: Standaert David G. , Testa Claudia M. , Young Anne B. , Penney John B. 
Published: January 2005

AbstractGlutamate is an important neurotransmitter in the circuitry of the basal ganglia. Of the four pharmacological classes of receptors that many mediate the actions of glutamate, the N‐methyl‐D‐aspartate (NMDA) type is of particular interest insofar as it has been implicated in the neural processes underlying long‐term synaptic plasticity as well as excitotoxic injury. NMDA ligand binding sites are abundant in the structures of the basal ganglia, and NMDA receptors have been linked to neuronal excitability, neuropeptide gene expression, and regulation of dopamine release in these regions. NMDA receptors are believed to be heterooligomers of subunits from two families: NMDAR1, encoded by a single gene but alternatively spliced to produce eight distinct isoforms (NMDAR1A–H), and NMDAR2, encode by four separate genes (NMDAR2A–D).We have used in situ hydridization with a total of 13 oligonucleotide probes to examine the expression of these genes in the rat basal ganglia. NMDAR1 subunits are expressed throughout the basal ganglia as well as in the rest of the brain; however, the alternatively spliced amino‐terminal region Insertion I is abundantly expressed only in the subthalamic nucleus and is not detectable in the neostriatum, globus pallidus, or substantia nigra pars compacta. In contrast, expression of the carboxy terminus segment Deletion I is prominent in the striatum but is not observed in other elements of the basal ganglia. NMDAR2 subunits also exhibit differential expression: NMDAR2B is abundant in the striatum, but NMDAR2A is present within the striatum only at low levels. NMDAR2C is present in the substantia nigra pars compacta only, while NMDAR2D exhibits an unusual distribution, with high levels of expression in the substantia nigra pars compacta, the subthalamic nucleus, the globus pallidus, and the ventral pallidum.Since each isoform of the NMDAR1 and NMDAR2 subunits can confer distinct properties on the resultant NMDA receptor, these data imply that there is a high degree of regional specialization in the properties of NMDA receptors within the basal ganglia. © 1994 Wiley‐Liss, Inc.
Light and electron microscopic immunocytochemical analysis of the neurovascular relationships of choline acetyltransferase and vasoactive intestinal polypeptide nerve terminals in the rat cerebral cortex
Authors: Chédotal Alain , Umbriaco Denis , Descarries Laurent , Hartman Boyd K. , Hamel Edith 
Published: January 2005

AbstractAcetylcholine or vasoactive intestinal peptide (VIP)nerve terminals closely related to intracortical blood vessels have previously been reported. Recent physiological evidence indicates that these central neuronal systems are involved in the fine control of local cerebral blood flow. In the present study, the intimate associations between choline acetyltransferase (ChAT) and VIP azon terminals and intracortical microvessels were characterized by light (LM) and electron microscopic (EM) immunocytochemistry. In semithin sections, LM analysis of the distribution of ChAT‐and VIP‐immunostained puncta juxtaposed to small intraparenchymal blood vessels demonstrated that neither type of terminal was enriched or improverished around microvessels within the cerebral cortex. At the EM level, most ChAT‐ or VIP ‐Immunolabelled elements located within a 3μm perimeter around vessel walls were axon terminals. These perivascular terminals were associated primarily with capillaries but also, to a lesser extent, with microarterioles. Even thought ChAT and VIP terminals were frequently found in the immediate vicinity (≤0.25 μm) of microvessels, they almost never contacted the outer basal lamina, usually abutting onto perivascular astroglial leaflets. There were no membrane specializations at the site of contact between ChAT or VIP terminals and perivascular astroglia. In all cortical areas examined, the average size of VIP‐Immunolabelled varicosities (0.56 ± 0.04 μm2) was significantly larger than that of their ChAT counterparts (0.32 ± 0.02 μm2; P< 0.001). Perivascular VIP terminals were more frequently engaged in synaptic contact than those immunostained for ChAT, which rarely exhibited a synaptic junction even in serial thin sections. Neither VIP nor ChAT immunostaining was ever observed in endothelial cells.These results suggest that both acetylcholine and VIP exert their effects on intracortical microvessels through indirect, paracrine mechanisms. The marked difference in synaptic incidence and average size between both types of perivascular terminals indicates that these two vasoactive agents are primarily located in distinct neuronal populations. Further, our results show that the astrocytic glia is the major direct target for both ChAT and VIP perivascular terminals and suggest that neuronal/glial/vascular interactions are a key element in the neurogenic control of the intracortical microcirculation. © 1994 Wiley‐Liss, Inc.
Density of peptide histidine‐isoleucine‐ and vasoactive intestinal peptide‐immunoreactive nerve fibers in the sheep pineal gland is not affected by superior cervical ganglionectomy
Authors: Cozzi B. , Mikkelsen J. D. , Ravault J.‐P. , Locatelli A. , Fahrenkrug J. , Zhang E.‐T. , Møller M. 
Published: January 2005

AbstractPeptide histidine‐isoleucine (PHI) is a regulatory peptide, synthesized as part of the same propeptide that includes also vasoactive intestinal peptide (VIP). The present study describes the distribution of PHI‐immunoreactive nerve fibers in the sheep pineal organ and compares their location with the distribution of VIP‐immunoreactive fibers in both normal and superior cervical ganglionectomized sheep in order to elucidate the origin of the PHI/VIP immunoreactive nerve fibers. Several PHI‐immunoreactive nerve fibers were present in the meninges and in the pineal capsule. Numerous positive nerve fibers entered the pineal gland and travelled within connective tissue spaces. Individual PHI‐positive nerve fibers were either smooth, without specialization, or varicose. Generally VIP‐ and PHI‐immunoreactive fibers were located close to connective septa and blood vessels. However, many PHIergic and VIPergic fibers possessing varicosities of variable sizes were also disperesed between pinealocytes. The distribution, density, and morphology of PHI‐ and VIP‐immunoreactive fibers in the sheep pineal gland were similar. In superior cervical ganglionectomized animals, intrapineal VIP‐ and PHI‐ immunoreactive nerve fibers were present with the same density as in control animals. In agreement, the concentration of immunoreactive VIP and PHI did not change after ganglionectomy. No VIP‐ and PHI‐immunoreactive cell bodies were observed in the superior cervical ganglia. Thus this study shows that the intrapineal VIP‐ and PHI‐immunoreactive nerve fibers do not originate from the sympathetic superior cervical ganglion. © 1994 Wiley‐Liss, Inc.
Distribution of substance P‐like immunoreactive neurons and terminals throughout the nucleus of the solitary tract in the human brainstem
Authors: McRitchie Deborah A. , Töurk Istvan 
Published: January 2005

AbstractThe anatomical distribution of substance P‐like immunoreactivity across the subnuclear divisions of the nucleus of the solitary tract has been examined in the human medulla oblongata. A differential distribution of neurons, fibers, and terminals was observed throughout the ten subnuclear divisions of this nucleus. Substance P‐like immunoreactive neurons were observed most frequently in the nucleus gelationsus, with moderate numbers in the medial, intermediate subnuclei and very few in the commissural, ventral, dorsal, and dorsolateral subnuclei. The paracommissural, ventrolateral, and interstitial subnuclei did not contain substance P‐like‐immunoreactive neurons. These neurons were typically bipolar and moderate‐sized to large, except for the neurons in the nucleus gelatinosus, which were substantially smaller. The highest densities of fibres and terminals were observed in the gelatinosus, medical, and intermediate nuclei, with moderate densities in the paracommissural and dorsal subnuclei. Sparse substance P‐like‐immunoreactive fibres and terminals were seen in the ventral and interstitial nuclei as well as within the solitary tract. The dorsolateral nucleus was characterized by a light distribution of fibres and terminals, except for a dense aggregation along its lateralmost border. A prominent innervation of pigmented neurons by substance P‐like‐immunoreactive terminals and fibres was also observed in the dorsolateral nucleus. The results reveal that the subnuclear complexity of the nucleus of the solitary tract is richly reflected by its differential pattern of substance P‐like‐immunoreactive structures. © 1994 Wiley‐Liss, Inc.
Horizontal cells and cone photoreceptors in primate retina: A Golgi‐light microscopic study of spectral connectivity
Authors: Ahnelt Peter , Kolb Helga 
Published: January 2005

AbstractThe relationship of primate horizontal cells (HC) to cone pedicles was assessed by superimposing the cone inner segment mosaic upon Golgi‐impregnated HC dendritic terminal clusters in a light microscope (LM) study. The HI, HII, and HIII types of HC were identified, hand‐drawn, photographed, and analyzed by computer graphics methods. Blue cone (B‐cones) inner segments and their projected pedicles were distinguished from red (R‐cones) and green (G‐cones) cones on morphological criteria. Thus the inclusion or avoidance of B‐cone pedicles by the various HC types dendritic terminal clusters establishes whether there is any color specificity to their connections. In addition, we made counts of the number of dendritic terminals in the clusters going to cone pedicles in the various HCs' dendritic fields and plotted these against distance the cone pedicles lay from the cell body. In this way we could evaluate the weighting of spectral type of cone input.In general, the three HC types made the majority of their dendritic contacts with cones lying closest to their cell bodies at the center of their dendritic fields. However, HI and HIII cells, with their distinct terminal clusters, did not contact all the centrally located cones uniformly. They either avoided completely (HIII cells) or made only sparse dendritic connections (HI cells) with certain cones. The avoided or sparsely innervated cones were identified as B‐connes. HII cells, on the other hand, with their more profuse and diffusely branched dendrites, appeared to contact all overlying cone pedicles and, in contrast to HI and HIII cells, directed a relatively larger number of dendrites to B‐cone positions. Axon terminals of HIII cells appeared to contact B‐cones exclusively. © 1994 Wiley‐Liss, Inc.
Differential localization of two glutamic acid decarboxylases (GAD65 and GAD67) in adult monkey visual cortex
Authors: Hendrickson A. E. , Tillakaratne N. J. K. , Mehra R. D. , Esclapez M. , Erickson A. , Vician L. , Tobin A. J. 
Published: January 2005

AbstractAdult monkey primary visual cortex contains a diverse population of stellate neurons that utilize the neurotransmitter γ aminobutyric acid (GABA). Two glutamic acid decarboxylase (GAD) enzymes that synthesize GABA, GAD65 and GAD67, were localized within these stellate neurons by in situ hybridization of 35S or digoxigenin (DIG) labeled riboprobes. Double labels were done by using 35S GAD67 riboprobe and GABA immunocytochemistry on the same section to verify that the neuronal population identified by immunocytochemistry was the same one studied in the in situ hybridization experiments.We find that GAD65 mRNA and GAD67 mRNA are widely distributed in the cortex, with four bands of heavily labeled neurons in upper layer 2, lower 3, 4C, and 6. GAD67 labeled neurons were more obvious in layer 4Cβ, while GAD65 containing neurons were common in layer 1 and white matter. Northern blots and in situ hybridization on sections with both 35S and DIG riboprobes indicate that cortical neurons typically contain more GAD67 mRNA. Cell counts show that 18% of all cortical neurons contain GAD67 mRNA and 13% contain GAD65 mRNA, suggesting that a small population of GABA neurons might lack GAD65. Cell bodies that contain high amounts of GAD65 mRNA are prominent in layers deep 3, 4B, 4Cα, and 6 and often are the largest cells in their respective layers. Double labels demonstrate that 96% of all GABA+ neurons contain GAD67 mRNA. Neurons heavily labeled for GABA tend to have smaller cell bodies and contain less GAD67 mRNA, while lightly labeled GABA neurons are larger and contain more GAD67 mRNA.These data indicate that most GABA neurons in monkey striate cortex contain both GAD enzymes. Although the differences in GABA content, cell size, laminar distribution, and GAD mRNA concentration suggest different requirements for GAD67 and GAD65 in cortical circuits, our experiments do not reveal what different roles these two enzymes subserve within GABAergic stellate neurons. © 1994 Wiley‐Liss, Inc.
Immunocytochemical characterization of the synaptic innervation of a single spinal neuron, the electric catfish electromotoneuron
Authors: Schikorski Thomas , Braun Norbert , Zimmermann Herbert 
Published: January 2005

AbstractThe electric catfish, Malapterurus electricus, possesses electric organs that are innervated by a pair of identifiable electromotoneurons located withi the cervical spinal cord. The pattern of synaptic innervation of the electromotoneurons can be revealed by an antibody against the synaptic vesicle protein SV2. Both somata and proximal dendrites are densely innervated. Several transmitters contribute to this punctuate immunoreactivity. The previously dorsal root sensory fibers, reveals a weak punctuate immunoreactivity. The previouslydescribed electrical synapses of the electromotoneurons wete visualized by an antibody against a gap‐ junctional protein. In contrast to the electromotoneurons of other electric fish, the electric catfish electromotoneurons possess many inhibitory synapses. With antibodies against glycine and against the glycinee receptor, a dense immunoreactivity of the surface of the somata and proximal dendrites can be revealed. The glycine receptor‐like immunoreactivity exhibits a patch‐like distribution similar to that revealed by the anti‐SV2 antibody. γ‐Aminobutyric acid (GABA)‐ immunopositive terminals contribute to the inhibitory electromotoneuron innervations to a lesser degree.The chemical characteristics of the electromotoneuron innervations of Malapterurusresemble those of other spinal motoneurons rather than electromotoneurons of other electric fish. Thus our immunocytochemical study supports the view that the pattern of electromotoneuron innervations in Malapterurus reveals little specialization. The capacity for information processing required for the control of the electric organ discharge appears to be achieved by the increased integrational capacity of the newly evolved multiple dendrites and not by an additional parallel channel specific for the electromotor system. © 1994 Wiley‐Liss, Inc.
Projections to the cochlear nuclei from principal cells in the medial nucleus of the trapezoid body in guinea pigs
Authors: Schofield Brett R. 
Published: January 2005

AbstractSpherical and globular cells in the cochlear nucleus provide input to the cell groups in the superior olivary complex devoted to the analysis of binaural cues. Desending projections from the superior olivary complex appear to inhibit the spherical and globular cells. It is not known which of the numerous cell types in the superior olive provide this descending input, but recent studies have shown that some of the cells are located in the medial nucleus of the trapezoid body (MTB). The present experiments were designed to determine whether the MTB projections arise from principal cells, which are known to play a role sound localization, and to determine whether their projections terminate on spherical or globular cells.Principal cells in the MTB are characterized by their contacts with synaptic specializations called calyces, which arise from the axons of cells in the contralateral cochlear nucleus. In the first experiment, a fluorescent tracer was injected into one cochlear nucleus to label the calyces anterogradely. A dfferent tracer was injected into the opposite cochlear nucleus to label cells retogradely in the MTB. In every case, some of the labeled cells were enveloped by a labeled calyx, demonstrating that principal cells do project to the cochlear nucleus. In the second experiment, fluorescent tracers were injected into different parts of the cochlear nucleus. Anaysis of the distribution of labeled cells suggested that MTB projections selectively target the globular cell region of the cochlear nucleus. In a third experiment, the axonal arborizations arising from this projection were labeled with biocytin or wheat germ agglutinin conjugated to horseradish peroxidase. Labeled boutons appeared to contact globular cels but not spherical cells. Multipolar cells in the ventral cochlear nucleus and cells in the dorsal cochlear nucleus were also contacted.The results suggest that MTB projections to the cochlear nucleus arise largely from principal cells and contact, at least in part, cells in the cochlear nucleus that give rise to ascending pathways involved in sound localization. © 1994 Wiley‐Liss, Inc.
Autoradiographic distribution of [3H]YM‐09151‐2, a high‐affinity and selective antagonist ligand for the dopamine D2 receptor group, in the rat brain and spinal cord
Authors: Yokoyama Chihiro , Okamura Hitoshi , Nakajima Teruo , Taguchi Jun‐Ichi , Ibata Yasuhiko 
Published: January 2005

AbstractWe determined the regional distribution of the dopamine D2 receptor group in the rat central nervous system by quantitative receptor autoradiography with a high‐affinity and selective antagonist, [3H]YM‐09151‐2. Saturation and competition experiments demonstrated that the binding of [3H]YM‐09151‐2 to striatal sections was saturable (Bmax=37.3 fmol/section), of high affinity (Kd=0.315 nM), and was inhibited selectively by prototypic D2 ligands.The anatomical localization of binding sites was determined by comparison of autoradiograms and the original 3H‐ligand‐exposed sections stained with cresyl violet. Very high levels of [3H] YM‐09151‐2 binding were found in the caudate‐putamen, nucleus accumbens, tuberculum olfactorium and the insula of Calleja, to each of which midbrain dopaminergic neurons project densely. High levels of binding were also observed in other regiions rich in dopaminergic neurons and fibers including the glomerular layer of the olfactory bulb, the intermediate lobe of the pituitary, lateral septum, substantia nigra pars compacta, interfascicular nucleus, dorsal raphe nucleus, locus coeruleus, and nucleus of the solitary tract. Some regions poor in dopaminergi innervation, however, had high levels of [3H]YM‐09151‐2 binding including the molecular layer of gyrus dentatus, all layers of CA1 and the nonpyramidal layer of CA4 of hippocampus, and the deeper layer of medial entorhinal cortex. Motor neurons present in brainstem motor nuclei and spinal ventral horn were also strongly labeled. Neocortical, cerebellar, and thalamic regions had low levels of binding, except lobules 9–10 of the cerebellum, the olivary pretectal nucleus, zona incerta and lateral mammillary nucleus, in which moderate to high levels of binding were detected. Our findings concerning the widespread but region‐specific localization of [3]YM‐09151‐2 binding sites in the brain and spinal cord may prove useful for analyzing varoius dopaminergic functions in the central nervous system. © 1994 Wiley‐Liss, Inc.
Neuroendocrine control of egg‐laying behavior in the nudibranch, Archidoris montereyensis
Authors: Wiens Brenda L. , Brownell Philp H. 
Published: January 2005

AbstractWe describe a group of neurons with egg‐laying bioactivity in the cerebral ganglia of an opisthobranch mollusc, the nudibranch Archidoris montereyensis. These cells, the intercerebral white cells (IWCs), share morphological, biochemical, and electrophysiological characteristics with the egg‐laying neuroendocrine cells of two other molluscs, Aplysia californica (bag cells) and Lymnaea stagnalis(caudodorsal cells). The IWCs, comprising two superficial clusters of about 100 neurons each, were located immediately posterior to the intercerebral commissure in the cerebral ganglia. The somata of these cells were small ( < 20 μm) and possessed varicose, bifurcating unipolar processes that collectively formed a loop within the commissure and bilateral extensions into the cerebral ganglia. The IWC clusters and commissural processes were enveloped by a large ganglionic vascular sinus, forming a potential neurohemal release site. Homogenates of whole cerebral ganglia or isolated IWC clusters induced egg‐laying behavior within hours of injection into the hemocoel of quiescent animals. The IWCs were immunoreactive for alpha bag‐cell peptide, one of the neuropeptide transmitters encoded by the egg‐laying hormone gene of Aplysia. Electrophysiologically, the IWCs were silent neurons with large resting potentials and appeared to be highly refractory to electrical stimulation. The similarities of the IWCs to the egg‐laying neuroendocrine cells in Aplysiaand Lymnaeasuggest that they are members of a homologous group of neurons controlling egg‐laying behavior in gastropod molluscs. © 1994 Wiley‐Liss, Inc.
Light and electron microscopic characterization of cholinergic and dopaminergic structures in the striatal complex and the dorsal ventricular ridge of the lizard Gekko gecko
Authors: Henselmans J. M. L. , Wouterlood F. G. 
Published: January 2005

AbstractThe purpose of the present study was to visualize the morphological substrate underlying acetylcholine‐dopamine interactions in the striatal complex of the lizard Gekko gecko and to compare the results with data obtained by others in mammals. The results are also discussed in the light of data obtained previously by us on neurochemical aspects of acetylcholine‐dopamine interactions in Gekko and in rats. The study is part of a large research program in which the cholinergic and dopaminergic elements of the striatum of rats, and reptiles are studied at morphological and neurochemical levels. We employed light microscopic immunocytochemistry, using single‐label staining with antibodies against choline acetyltransferase (ChAT) and dopamine (DA) and double‐staining with antibodies against ChAT and tyrosine hydroxylase (TH). A detailed analysis of ultrastructural characteristics of ChAT‐ and DA‐immunolabeled striatal tissue was undertaken.The morphology and synaptic relations of the ChAT‐immunopositive neurons in the basal forebrain of the lizard Gekko gecko are very similar to those of the cholinergic cells in the striatum of mammals. Probably, the cholinergic cells are in both mammals and reptiles interneurons that receive inputs of intrinsic or extrinsic origin and project upon output neurons. The location of ChAT‐immunopositive somata outside the patches of high TH‐ or DA‐immunoreactivity is at odds with the situation in the striatum of mammals and suggests the possibility of axoaxonal or axodendritic contacts at the level of these patches. We found no essential differences between the synaptic relations of the dopaminergic fibers in the striatal complex of Gekko and the conditions described for rats.In conclusion, we found little evidence for the presence of synaptic interaction between the cholinergic and dopamindrgic systems in the striatum of this reptile. The possibility of nonsynaptic interaction, however, remains open. © 1994 Wiley‐Liss, Inc.