bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunohistochemical organization of the ventral lateral geniculate nucleus in the ground squirrel
Authors: Agarwala Seema , May Jack G. , Moore Jean K. , Petry Heywood M. 
Published: January 2005

AbstractThe ventral lateral geniculate nucleus (vLGN) of the thirteen‐lined ground squirrel (Citellus tridecemlineatus) is a highly differentiated nucleus that is divisible into five major subdivisions on the basis of retinal projections and cytoarchitecture. To pursue the likelihood that these subdivisions (the dorsal cap, intergeniculate leaflet, external magnocellular lamina, internal magnocellular lamina, and parvicellular segment) correlate with the functional diversity of this complex, the present study examined the neurochemical composition of the vLGN with regard to substances that have previously proved useful in distinguishing functionally distinct subregions within nuclei (i.e., neuropeptide Y (NPY), substance P (SP), leucine and methionine enkephalins, gamma‐aminobutyric acid (GABA), cytochrome oxidase (CO), acetylcholinesterase (AChE), and NADPH‐diaphorase).The results showed a clear differential neurochemical distribution within the nucleus. Neuropeptide Y immunoreactive perikarya were found predominantly in the intergeniculate leaflet and external magnocellular lamina, with only a few present in the internal magnocellular lamina and dorsal cap, and none observed in the parvicellular segment. NPY+ fibers, however, were present in all divisions except the parvicellular segment. The highest concentration of SP immunoreactive cells was observed in the internal magnocellular lamina, and substantial numbers also were scattered in the external magnocellular lamina and parvicellular segment. SP+ fibers were seen predominantly in the intergeniculate leaflet and the magnocellular laminae. The heaviest concentration of enkephalinergic fibers occurred in the internal magnocellular lamina and dorsal cap, but fibers were also observed in the external magnocellular lamina and intergeniculate leaflet. GABA reactivity was widespread throughout the vLGN, with the dorsal cap and external magnocellular lamina most heavily labeled, followed by the intergeniculate leaflet and the internal magnocellular lamina. Cytochrome oxidase, AChE, and NADPH‐diaphorase histochemistry revealed rich reactivity within the dorsal cap, and external and internal magnocellular laminae and paler reactivity in the intergeniculate leaflet and parvicellular segment. The external magnocellular lamina was more reactive for CO and NADPH‐diaphorase than AChE, while the internal magnocellular lamina showed the opposite pattern of reactivity. In addition, NADPH‐diaphorase reactive cells were present in caudal intergeniculate leaflet and lateral external magnocellular lamina.These local differences in the neurochemical character of the vLGN support its parcellation into multiple subdivisions. Taken in conjunction with the differences in cytoarchitecture and retinal projections, these results suggest substantial function diversity within the ventral lateral geniculate complex.
Antennular projections to the midbrain of the spiny lobster. I. Sensory innervation of the lateral and medial antennular neuropils
Authors: Schmidt Manfred , Van Ekeris Leslie , Ache Barry W. 
Published: January 2005

AbstractThe organization of sensory afferents in the antennular nerve (AN) of the spiny lobster and the central arborization of the afferents in the lateral and medial antennular neuropils (LAN, MAN) were analyzed by backfilling the AN with biocytin. The MAN receives primarily thick afferents (diameter ≥ 10 μm) with a consistent pattern of arborization from the medial of the three major divisions of the AN. The LAN, in contrast, receives many thin to medium‐sized afferents (diameter ≤ 0.3–5 μm), in addition some with diameters ≥ 5 μm, from the lateral and dorsal divisions of the AN. In contrast to the consistent pattern of arborization in the MAN, afferents projecting to the LAN arborize in widely different patterns. Serially arranged, orthogonal side branches that are suggestive of topographical representation of the serially arranged sensilla on the antennule contribute to the stratification of the LAN. Together with existing electrophysiological data, these morphological findings are consistent with the idea that the MAN receives primarily mechanosensory (largely statocyst) input, as previously thought, but that the LAN receives chemosensory as well as mechanosensory input. The chemosensory input to the LAN would represent a novel pathway for processing chemosensory input from the antennule.
Light and electron immunocytochemical localization of AMPA‐selective glutamate receptors in the rat brain
Authors: Petralia Ronald S. , Wenthold Robert J. 
Published: January 2005

AbstractSince four AMPA‐type excitatory amino acid receptor subunits have been cloned recently, it is now possible to localize these important molecules in the nervous system. A comprehensive study of AMPA receptor immunocytochemistry was carried out on vibratome sections of rat brain, which were immunolabeled with antibodies made against peptides corresponding to the C‐terminal portions of AMPA‐receptor subunits: GluR1, GluR2/3, and GluR4. Labeling was most prominent in forebrain structures such as the olfactory bulb and tubercle, septal nuclei, amygdaloid complex, hippocampus, induseum griseum, habenula, and interpeduncular nucleus, and in the cerebellum. Different patterns of immunolabeling were evident with the antibodies to the four subunits, with marked contrast between densely and lightly stained structures with antibody to GluR1, widespread dense staining with antibody to GluR2/3, and moderate staining with antibody to GluR4. In the parietal cortex, some non‐pyramidal neurons were more densely stained than pyramidal cells with antibodies to GluR1. Neurons of the main olfactory bulb, other than granule cells, were most densely stained with antibody to GluR1. In the cerebellum, Bergmann glia were densely stained with antibodies to GluR1 and 4, while neurons, other than granule cells, were most densely stained with antibody to GluR2/3. Immunolabeling patterns of all antibodies were consistent with that of previous in situ hybridization histochemistry studies and with the overall pattern of 3H‐AMPA binding. Electron microscopy of thin sections taken from immunolabeled vibratome sections of hippocampus and cerebral cortex showed staining which was restricted mainly to postsynaptic densities and adjacent dendritoplasm, and to neuron cell body cytoplasm. We saw no convincing examples of stained presynaptic terminals, and only limited evidence of glial staining, excepting Bergmann glia.
Lateral geniculate projections to the superficial layers of visual cortex in the tree shrew
Authors: Usrey W. Martin , Muly E. Christopher , Fitzpatrick David 
Published: January 2005

AbstractOur recent studies of tree shrew striate cortex have focused on the organization of lateral geniculate projections to layer IV and the projections from IV to layer III. Although these pathways play an important role in determining the response properties of layer III neurons, there are additional pathways from the lateral geniculate nucleus (LGN) that terminate directly in layer III. Previous studies provided evidence that these projections originate from layers 6 and 3 of the LGN and terminate in different subdivisions of layer III. In this study we used injections of biocytin to examine the projections of layers 6 and 3 to the cortex in more detail.Consistent with earlier work, we found that LGN layer 6 projects heavily to lower IIIc, while LGN layer 3 terminates densely in layer IIIb and sparsely throughout layers IIIa‐I. In addition, we found that neurons in layers 6 and 3 have collateral projections: neurons in LGN layer 6 project to the bottom of layer IVb and sparsely to I–IIIb; neurons in LGN layer 3 project sparsely to layers V and VI and to the middle of IV.These patterns of projections are significant in the light of our studies of the connections from cortical layer IV to layer III. LGN projections to the superficial layers are organized into parallel pathways that exert selective influence over different populations of neurons in layers I–III and on the layer IV neurons that supply them. © 1992 Wiley‐Liss, Inc.
Pyramidal neurons of the rat cerebral cortex, immunoreactive to nicotinic acetylcholine receptors, project mainly to subcortical targets
Authors: Bravo Hermes , Karten Harvey J. 
Published: January 2005

AbstractCortical neurons immunoreactive to nicotinic acetylcholine receptors (nAChR) of the rat brain were characterized with monoclonal antibodies directed to ACh‐binding subunits (alpha 4) or to ACh‐structural subunits (beta2). A heterogeneous population of nAChR‐LI neurons was found in all cortical regions. The most prominent immunoreactive neurons were pyramids of layers V and II–III. The nonpyramidal positive neurons were fusiform horizontally oriented neurons of layer VIb, small cells of layer I and round or ovoid neurons of layers II–V.Double labeled experiments (immunohistochemistry and fluorescent retrograde tracers) showed that cholinoceptive pyramidal neurons of layer V project mainly to subcortical targets such as caudate‐putamen, superior colliculus, and pontine nuclei, while very few nAChR positive neurons connect to other cortical areas. These findings suggest that the mainly excitatory effect that has been attributed to the cholinergic innervation upon the cortical neurons may have a greater influence upon the cortico‐subcortical output than the corticocortical one.
Prefrontal cortical efferents in the rat synapse on unlabeled neuronal targets of catecholamine terminals in the nucleus accumbens septi and on dopamine neurons in the ventral tegmental area
Authors: Sesack Susan R. , Pickel Virginia M. 
Published: January 2005

AbstractPhysiological and pharmacological studies indicate that descending projections from the prefrontal cortex modulate dopaminergic transmission in the nucleus accumbens septi and ventral tegmental area. We investigated the ultrastructural bases for these interactions in rat by examining the synaptic associations between prefrontal cortical terminals labeled with anterograde markers (lesion‐induced degeneration or transport of Phaseolus vulgaris leucoagglutinin; PHA‐L) and neuronal processes containing immunoreactivity for the catecholamine synthesizing enzyme, tryosine hydroxylase.Prefrontal cortical terminals in the nucleus accumbens and ventral tegmental area contained clear, round vesicles and formed primarily asymmetric synapses on spines or small dendrites. In the ventral tegmental area, these terminals also formed asymmetric synapses on large dendrites and a few symmetric axodendritic synapses. In the nucleus accumbens septi, degenerating prefrontal cortical terminals synapsed on spiny dendrites which received convergent input from terminals containing peroxidase immunoreactivity for tyrosine hydroxylase, or from unlabeled terminals. In single sections, some tyrosine hydroxylase‐labeled terminals formed thin and punctate symmetric synapses with dendritic shafts, or the heads and necks of spines. Close appositions, but not axo‐axonic synapses, were frequently observed between degenerating prefrontal cortical afferents and tyrosine hydroxylase‐labeled or unlabeled terminals. In the ventral tegmental area, prefrontal cortical terminals labeled with immunoperoxidase for PHA‐L were in synaptic contact with dendrites containing immunogold reaction product for tyrosine hydroxylase, or with unlabeled dendrites.These results suggest that: (1) catecholaminergic (mainly dopaminergic) and prefrontal cortical terminals in the nucleus accumbens septi dually synapse on common spiny neurons; and (2) dopaminergic neurons in the ventral tegmental area receive monosynaptic input from prefrontal cortical afferents. This study provides the first ultrastructural basis for multiple sites of cellular interaction between prefrontal cortical efferents and mesolimbic dopaminergic neurons.
Patterns of antigenic expression in the thalamic reticular nucleus of developing rats
Authors: Mitrofanis John 
Published: January 2005

AbstractThe present study describes the development of the thalamic reticular nucleus in rats with the use of Nissl staining and antibodies to parvalbumin and pro‐α‐thyrotropin‐releasing hormone (αTRH). Two major subdivisions of the reticular nucleus are apparent: (1) the main body, which is itself heterogeneous and lies for the most part between the fibres of the internal capsule and external medullary lamina, and (2) the perireticular nucleus, which lies lateral to the main body and medial to the globus pallidus.In the main body of the reticular nucleus of adults, most cells in all regions are immunoreactive to parvalbumin and αTRH. During development there are two waves of parvalbumin and αTRH expression. The first wave occurs between postnatal day (P) 0 and P10, and labelled cells are apparent in rostrolateral areas of the main body of the nucleus only. At P10, such cells are not apparent. From P7 to adult, there is a second wave of parvalbumin and αTRH expression: labelled cells emerge first in central, then in caudal, and finally in rostral areas of the nucleus.In adults, the perireticular nucleus is made up of a few small cells which are immunostained for parvalbumin and αTRH. These cells are more frequent in areas of the internal capsule adjacent to the ventral regions of the main body of the reticular nucleus, rostrodorsal to the entopeduncular nucleus. From E (embryonic day) 17 to about P10, the perireticular nucleus consists of a surprisingly large population of neurones, many of which are parvalbumin and αTRH immunoreactive. By about P10, as in adults, there are few perireticular cells.
Somatosensory receptive field properties of corpus callosum fibres in the raccoon
Authors: Guillemot Jean‐Paul , Richer Louis , Ptito Maurice , Guilbert Michel , Lepore Franco 
Published: January 2005

AbstractAnatomical studies in a number of species have shown that most areas of the somatosensory cortex are callosally interconnected. This is also true for the raccoon, at least for those parts representing proximal and axial body regions. Electrophysiologically, studies carried out in cats and monkeys have demonstrated that all sensory sub‐modalities cross in the callosum. Moreover, cells representing the paws and fingers, though occupying a large portion of areas SI and SII, seem to send proportionately fewer axons through the callosum than axial structures. No comparable study has been carried out in the raccoon. The purpose of the present experiment was therefore to investigate the functional organization of the callosal system in this animal by examining the receptive field properties of the somatosensory fibres crossing in the callosum.Axonal activity was recorded directly through tungsten microelectrodes in the corpus callosum of eight raccoons. Results indicated that somatosensory information is transmitted in its rostral portion. Most receptive fields concerned axial and proximal body regions and the head and face. Some receptive fields represented para‐axial regions of the body and a few concerned the hands and fingers. Slowly and rapidly adapting fibres were found, as were all the sensory sub‐modalities tested. A substantial proportion of the axons had bilateral receptive fields.These results are discussed in relation to those obtained in other species, with particular reference to: (1) the midline fusion hypothesis of callosal function; (2) the representation within this structure of the distal extremities, and (3) the origin of the bilateral receptive fields. © 1992 Wiley‐Liss, Inc.
Common synaptic drive to segmentally homologous interneurons in the locust
Authors: Boyan George 
Published: January 2005

AbstractThe aim of the present study was to examine the pattern of synaptic interactions among a set of identified homologous interneurons in the segmental nervous system of the locust.This paper presents two main findings: first, serially homologous interneurons that are the progeny of neuroblast 7‐4 in the mesothoracic, metathoracic, and first abdominal neuromeres of the locust central nervous system all receive synaptic drive from one and the same presynaptic interneuron. This interneuron has its entire arborization located in these three neuromeres of the central nervous system. It synapses with cells that are siblings, bilateral homologs, and serial homologs, and is itself connected monosynaptically with auditory afferents. The neuronal network that results comprises postsynaptic cells with the same developmental lineage. The second finding is that there is an additional set of synaptic connections among the homologous neurons themselves. All these connections are excitatory, and the pattern of information flow within the network is highly directional. This may relate to the morphologies of the neurons involved and will influence the contribution of homologs from different segments to behavior. © 1992 Wiley‐Liss, Inc.
Ventral pallido‐striatal pathway in the rat brain: A light and electron microscopic study
Authors: Kuo H. , Chang H. T. 
Published: January 2005

AbstractMost theories of basal ganglia functions have been based on a model circuit in which the flow of information follows a one‐way loop proceeding from the cerebral cortex to the striatum, the pallidum/nigra, the thalamus, and then returns to the cortex. However, this model neglects data from several studies that show a direct feedback projection from the pallidum to the striatum. In this study, we have examined this feedback connection in the ventral striopallidal system to determine the morphology and chemical properties of ventral pallido‐striatal projection neurons and to determine the morphology of ventral pallidal efferents in the ventral striatum.Fluoro Gold was injected into the ventral striatum to retrogradely label ventral pallidal projection neurons. Substance P immunoreactivity was used as a pallidal marker to delineate the ventral pallidum. The results show that most neurons retrogradely labeled by Fluoro Gold lie in the ventral pallidum. Additional double‐labeling experiments show that none of these Fluoro Gold‐labeled cells are cholinergic neurons; however, some are immunoreactive for parvalbumin, a calcium‐binding protein found in many pallidal neurons. Electron microscopy revealed that the somata and dendrites of these labeled ventral pallidal projection neurons form many synapses with unlabeled terminals. Injection of Phaseolus vulgaris‐leucoagglutinin into the ventral pallidum anterogradely labeled many fibers in the ventral striatum. Electron microscopy revealed that these labeled axons form both symmetric and asymmetric synapses with ventral striatal neurons.We have thus confirmed that there is a significant direct projection from the ventral pallidum to the ventral striatum. Whether this projection forms a part of either monosynaptic or polysynaptic feedback loops remains to be clarified. Nevertheless, this pallidostriatal projection must be integrated into the theories on basal ganglia functions. © 1992 Wiley‐Liss, Inc.
A new specific antibody reveals octopamine‐like immunoreactivity in cockroach ventral nerve cord
Authors: Eckert Manfred , Rapus Jürgen , Nürnberger Asja , Penzlin Heinz 
Published: January 2005

AbstractAn antiserum was raised in rabbits immunized with octopamine conjugated to thyroglobulin. The specificity of this antiserum for octopamine is shown by dot blot immunoassay analysis. The antiserum does not crossreact with dopamine, noradrenaline, and serotonin, but slight crossreactivity with the amine tyramine at high concentrations was observed. The tyramine crossreactivity could be eliminated by preabsorption with a tyramine‐glutaraldehyde‐BSA conjugate. Using this antiserum, we describe the topographical distribution of octopamine‐immunoreactive (ir) neuronal elements in wholemounts and paraffin sections of the ventral nerve cord of the American cockroach. The pattern of octopamine immunostaining is completely different from that obtained with an antidopamine serum, and can be blocked by preabsorbing the antioctopamine serum with BSA‐conjugated octopamine.Cell bodies and dendritic processes of putatively octopaminergic dorsal (DUM) and ventral (VUM) unpaired median neurons were clearly octopamine‐ir in all ganglia examined. The numbers of stained DUM somata in the mesothoracic, metathoracic, and terminal ganglion of females correspond to those of peripherally projecting DUM cells revealed previously by retrograde tracing (Gregory, Philos Trans R Soc Lond [Biol] 306:191, 1984; Tanaka and Washio, Comp Biochem Physiol 91A:37, 1988; Stoya et al., Zool Jb Physiol 93:75, 1989). In addition, various, previously unknown, paired cells with octopamine‐like immunoreactivity were found in all ventral ganglia except abdominal ganglia 3–6. Some of these probably project intersegmentally. © 1992 Wiley‐Liss, Inc.
Distribution of protein gene product 9.5 (PGP 9.5) in the vertebrate retina: Evidence that immunoreactivity is restricted to mammalian horizontal and ganglion cells
Authors: Bonfanti Luca , Candeo Paola , Piccinini Marco , Carmignoto Giorgio , Comelli Maria Cristina , Ghidella Silvana , Bruno Renato , Gobetto Armando , Merighi Adalberto 
Published: January 2005

AbstractUsing light microscopic immunocytochemistry, we have studied the distribution of protein gene product 9.5 (PGP 9.5), a neuron‐specific protein first extracted from human brain (Doran et al., '83: J. Neurochem. 40:1542–1547), in the vertebrate retina. Retinas were obtained from frog, chicken, rat, rabbit, cow, cat, dog, and human. No immunoreactivity was observed in frog and only a faint staining was present in chicken. In mammalian retinas, a strong positive reaction was restricted to horizontal and ganglion cells, with minor interspecies variations. Immunostaining was present throughout the cell body and the dendritic tree in horizontal cells. At the level of retinal ganglion cells, immunolabel was particularly abundant in cell bodies and axons forming the optic nerve. Only the main dendrites were stained, the remainder of the dendritic tree giving rise to a diffuse punctate reaction in the inner plexiform layer. In rats, displaced amacrine cells, which are known to contribute largely (40–50%) to the total neuronal population within the ganglion cell layer (Perry, '81: Neuroscience 6:931–944) were not immunoreactive, as demonstrated from (i) analysis of the morphology, cell size and cell density of immunoreactive neurons in wholemounts; (ii) colocalization of retrograde label and PGP 9.5 immunoreactivity in about 80% of ganglion cells after injection of peroxidase into the optic nerve; and (iii) reduction of immunoreactivity in the inner plexiform and ganglion cell layers following optic nerve transection.Western blot analysis of extracts from rabbit retinas indicated that the immunoreactive species is PGP 9.5 or a closely related molecule. Recent studies have demonstrated that PGP 9.5 is a ubiquitin carboxyl‐terminal hydrolase (Wilkinson et al., '89: Science 246:670–673). The present results, therefore, suggest that differences in the ubiquitination process exist between retinal neurons. © 1992 Wiley‐Liss, Inc.