摘要:

AbstractWe examined the projection from the basal forebrain to thalamic and cortical regions of the visual system in cats, with particular reference to the visual sector of the thalamic reticular nucleus, the lateral geniculate nucleus, and the striate cortex. First, we made injections of wheat germ agglutinin conjugated to horseradish peroxidase (WGA‐HRP) into the visual sector of the thalamic reticular nucleus and found cells labeled by retrograde transport in the lateral nucleus basalis magnocellularis. Injection of biocytin into the basal forebrain resulted in the anterograde labeling of a dense band of fibers and terminals within the entire thalamic reticular nucleus; this labeling extended through the visual sector including the perigeniculate nucleus. No orthograde labeling was found in the lateral geniculate nucleus. Next, we addressed the issue of putative neurotransmitters used by this pathway using a variety of immunocytochemical and histochemical markers. In this fashion, we identified two populations of cells in the nucleus basalis magnocellularis of the cat: large cholinergic cells that contain choline acetyltransferase, NADPH‐diaphorase, and calbindin and that project to striate cortex and smaller cells that contain gamma‐aminobutyric acid (GABA), glutamic acid decarboxylase, and parvalbumin and that project to the visual sector of the thalamic reticular nucleus. We also examined at the electron microscopic level terminals in the visual sector of the thalamic reticular nucleus that were labeled from a biocytin injection in the basal forebrain. Most of these terminals form symmetric contacts onto dendrites and were revealed by postembedding immunocytochemical staining to be positive for GABA. © 1994 Wiley‐L

ISSN:0092-7317    

DOI:10.1002/cne.903480402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe distribution of neurotensin (NT) was studied in the brain of three species belonging to the three major classes of cold‐blooded vertebrates: teleost fishes (Carassius auratus), anuran amphibians (Hyla meridionalis), and reptiles (Gallotia galloti; Lacertidae). By using antibodies directed against synthetic bovine NT in the three species, immunoreactive cell bodies were discovered mostly in the telencephalon and diencephalon, in particular at the level of the preoptic region the mediobasal hypothalamus, and the thalamus. In the frog and the lizard, additional immunoreactive (ir) structures were observed in the optic tectum and the tegmentum of the mesencephalon. In the goldfish pituitary, an extensive innervation was consistently observed at the level of the rostral pars distalis, whereas in both frog and lizard, positive fibers were only detected in the external layer of the median eminence. In the three species there is a striking overlap between the distribution of the NT‐ir cell bodies and that of the target cells for sexual steroids. The results are discussed in relation with those reported in birds and mammals, and with the possible interactions among NT, sexual steroids, and the neuroendocrine control of pituitary hormone release, in particular prolactin and gonadotrophin. © 1994 Wiley‐Lis

ISSN:0092-7317    

DOI:10.1002/cne.903480403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractDevelopment of the carotid body and the glomus cell groups in the wall of the common carotid artery and its branches was examined in chickens at various developmental stages by immunohistochemistry using three different monoclonal antibodies, i. e., anti‐neuron‐specific class III β‐tubulin isotype (TuJ1), anti‐rat brain β‐tubulin, and anti‐Leu‐7 (HNK‐1) antibodies. All the antibodies reacted with neurons. The carotid body anlage was first discerned at 6 days of incubation at the lateral portion of the third branchial artery. The cells and nerve fibers immunoreactive for TuJ1, brain β‐tubulin and Leu‐7, which were connected with the distal ganglion of the vagus nerve, were found around the carotid body anlage at this stage. Within the carotid body anlage, no immunoreactivity yet appeared. The immunoreactive cells were accumulated around the carotid body anlage until 8 days of incubation. From 9 days of incubation, the immunoreactive cells continuing with the distal vagal ganglion began to enter into the carotid body anlage and also dispersed widely along the common carotid artery and its branches, giving rise to the glomus cells. At 12 days of incubation, a large portion of the carotid body was occupied by the immunoreactive cells. Thus, the present study evidences that the glomus cells in the carotid body and around the arteries are emigrés that arrive in each residential place from the distal vagal ganglion. Immunoreactivity for TuJ1, brain β‐tubulin, and Leu‐7 in the glomus cells started to decrease at late stages of embryonic development. After hatching, no TuJ1‐immunoreactive cells were detected in the carotid body

ISSN:0092-7317    

DOI:10.1002/cne.903480404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractDevelopment of the carotid body and the glomus cell groups in the wall of the common carotid artery and its branches was studied in chickens at various developmental stages by electron microscopy. At 8 days of incubation, the carotid body anlage consisted of mesenchyme‐like cells, whereas the clusters of epithelial cells, which occasionally contained a few dense‐cored vesicles and were accompanied by unmyelinated nerve fibers, were located in the region surrounding the carotid body anlage and in the wall of the common carotid artery. Subsequently, the granule‐containing cells together with nerve fibers were detected in the periphery of the carotid body anlage. At 12 days of incubation, a large number of granule‐containing cells (glomus cells) were dispersed throughout the carotid body parenchyma and were also widely distributed along the common carotid artery and its branches. The cells frequently extended long cytoplasmic processes that made contact with other glomus cells and nerve fibers. Synaptic junctions which showed desmosome‐like thickening of pre‐ and postsynaptic membranes and accumulations of small clear vesicles (around 50 nm in diameter) were first detected along the contact between the long axons and glomus cells at 12 days of incubation. In the wall of the common carotid artery, interdigitations between the cytoplasmic processes of glomus cells and smooth muscle cells began to form. Sustentacular cells investing partly the glomus cells were also discerned both in the carotid body and around the arteries at this stage. At 14 days of incubation, the glomus cells expressed most of the characteristics of the mature cells, and the synaptic junctions displaying afferent morphology appeared; the secretory granules of glomus cells were accumulated near and attached to the desmosome‐like thickening of apposed membranes. © 1994 W

ISSN:0092-7317    

DOI:10.1002/cne.903480405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe relationship of the calcium binding protein parvalbumin (PV) with gamma‐aminobutyric acidergic (GABAergic) neurons differs within different thalamic nuclei and animal species. In this study, the distribution of PV and GABA throughout the thalamus of the guinea pig was investigated at the light microscopic level by using immunoperoxidase methods. Intense PV labelling was found in all the GABAergic neurons of the reticular nucleus and in scattered GABAergic neurons in the anteroventral nucleus, whereas GABAergic interneurons in the ventrobasal and lateral geniculate nuclei were not PV labelled.At the electron microscopic level, preembedding immunuperoxidase for PV was combined with postembedding immunogold for GABA. In the ventrobasal nucleus, four types of profiles were recognized: 1) terminals with flattened vesicles and forming symmetric synapses, which were labelled with both PV and GABA and could therefore be identified as afferents from the reticular nucleus; 2) boutons morphologically similar to presynaptic dendrites of interneurons, labelled only with GABA; 3) large terminals with round vesicles and asymmetric synapses, labelled only with PV, which contacted GABAergic presynaptic dendrites in glomerular arrangements and resembled ascending excitatory afferents; and 4) terminals unlabelled by either antiserum.In the ventrobasal nucleus of the guinea pig a double immunocytochemical labelling permits therefore the differentiation of two populations of GABAergic vesicle‐containing profiles, i. e., the terminals originating from reticular nucleus (that are double labelled) and the presynaptic dendrites originating from interneurons (that are GABA‐labelled only). The possibility to differentiate GABAergic inputs from the reticular nucleus and from interneurons can shed light to the functional interpretation of synaptic circuits in thalamic sensory nuclei. © 1994 Wiley‐L

ISSN:0092-7317    

DOI:10.1002/cne.903480406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe localization of the N‐methyl‐D‐aspartate receptor subunit NR2A was studied, by using light microscopic immunocytochemistry, in the retina of adult rat, rabbit, cat, and monkey. Strong, punctate immunolabeling was observed in the inner plexiform layer indicating a synaptic localization of the NR2A subunit. The punctate labeling was concentrated in two bands corresponding to the on‐ and off‐sublaminae of the inner plexiform layer.The punctate character of immunofluorescence suggested a synaptic localization of the receptor. This was confirmed by electron microscopy of immunostained adult rat retina. The staining was localized postsynaptic to cone bipolar cells, and only one of the two postsynaptic elements of the dyad was labeled. Staining was not observed at extrasynaptic plasma membranes.In situ hybridization of adult rat retina showed expression of the NR2A subunit in virtually all ganglion cells and displaced amacrine cells in the ganglion cell layer and in a subset of amacrine cells in the inner nuclear layer.The postnatal developmental expression of the NR2A subunit was studied in rat retina by light microscopic immunocytochemistry. Punctate immunolabeling appeared prior to eye opening, and the developmental profile of NR2A could be compatible with a role in development of circuitry in the inner plexiform layer. © 1994 Wiley

ISSN:0092-7317    

DOI:10.1002/cne.903480407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe organization of putative octopaminergic pathways in the brain and subesophageal ganglion of the honeybee was investigated with a well‐defined polyclonal antiserum against octopamine. Five prominent groups of just over 100 immunoreactive (IR) somata were found in the cerebral ganglion: Neurosecretory cells in the pars intercerebralis innervating the corpora cardiaca via NCC I, one cluster mediodorsal to the antennal lobe, one scattered on both sides of the midline of the protocerebrum, one between the lateral protocerebral lobes and the dorsal lobes, and a single soma on either side of the central body. With the exception of the pedunculi and β‐lobes of the mushroom bodies, varicose immunoreactive fibers penetrate all parts of the cerebral ganglion. Strong labelling was found in the central complex and the protocerebral bridge. Fine networks of labelled processes invade the antennal lobes, the calyces and a small part of the α‐lobes of the mushroom bodies, the protocerebrum, and all three optic ganglia.In the subesophageal ganglion, one labelled cell body was found in the lateral soma layer of the mandibular segment. Each of the three neuromeres contains a group of six to ten somata in the ventral median parts. Most of the ventral median cells send their neurites dorsally through the midline tracts, whereas the neurites of a few cells follow the ventral cell body neurite tracts.Octopamine‐IR was demonstrated in all neuropils that contain pathways for proboscis extension learning in honeybees. Because octopaminergic mechanisms seem to be involved in the behavioral plasticity of the proboscis extension reflex, our study provides anatomical data on the neurochemical organization of an appetitive learning paradigm. © 1994 Wiley

ISSN:0092-7317    

DOI:10.1002/cne.903480408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractWe describe the cloning and expression pattern of a new paired‐class homeobox gene, Vsx‐1, in the continuously growing retina of the goldfish. Vsx‐1 belongs to a subset of paired‐class homeobox genes that lack a second DNA binding domain, the paired‐domain, and is closely related to theC. elegansceh‐10 gene. In the adult goldfish, Vsx‐1 expression is restricted to the neural retina. In the central, mature retina, Vsx‐1 mRNA is synthesized in a subset of differentiated cells in the inner nuclear layer in a pattern suggestive of bipolar cells. In immature retina, adjacent to the retinal margin, Vsx‐1 is expressed in a relatively broader subset of newly postmitotic cells but is downregulated in some of these cells to form the mature expression pattern. Following retinal injury, during the early phase of regeneration, Vsx‐1 mRNA synthesis appears tp be upregulated in cells in the inner nuclear layer and is expressed de novo in cells outside this layer. By virtue of its identity as a transcriptional regulatory gene and its patterns of expression, we speculate that Vsx‐1 may stabilize the differentiated state of a subset of cells in the inner nuclear layer and may be involved in cellular differentiation during retinal development and regeneration.

ISSN:0092-7317    

DOI:10.1002/cne.903480409

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractTransfer of visual information from photoreceptors to ganglion cells within the retina is mediated by specialized groups of bipolar cells. At least 10 different morphological types of bipolar cells have been distinguished in Golgi studies of primate retina. In the present study, bipolar cell populations in the macaque monkey retina were identified by their differential immunoreactivity to a spectrum of antibody markers. This enabled their spatial density and photoreceptor connections to be analysed. An antibody against the β isozyme of protein kinase C (PKCAβ) labelled many cone bipolar cells. Invaginating (presumed ON) cone bipolar cells and rod bipolar cells were prefentially labelled with a monoclonal antibody raised against rabbit olfactory bulb. Flat (presumed OFF) bipolar cells were labelled with an antiserum against the glutamate transporter protein (GLT‐1).Different populations of diffuse cone bipolar cells, which contact 5–10 cones, could be distinguished. The GLT‐1 artiserum preferentially labelled the flat diffuse bipolar cell type DB2 (Boycott and Wässle, 1991, Eur. J. Neurosci.3:1069–1088) as well as flat midget bipolar cells. Antibodies to calbindin (CaBP D‐28K) labelled the flat diffuse bipolar cell type DB3 and (possibly) the invaginating diffuse bipolar cell type DB5. An antibody against the α isozyme of PKC labelled an invaginating diffuse bipolar cell type (DB4) as well as rod bipolar cells. Comparison of the spatial density of cone bipolar cell populations with that of photoreceptors suggests that each bipolar cell class provides a complete coverage of the cone array (each cone is contacted by at least one member of every bipolar cell class). These results support the classification scheme of Boycott and Wässle (1991) by showing that different diffuse bipolar cell classes express different patterns of immunoreactivity, and they reinforce the view that different spatial and temporal components of the signal from the photoreceptor array are processed in parallel within the primate retina. © 1994

ISSN:0092-7317    

DOI:10.1002/cne.903480410

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

ISSN:0092-7317    

DOI:10.1002/cne.903480401

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY