journal article
LitStream Collection
Home
Brunken, William J.; Witkovsky, Paul; Karten, Harvey J.
doi: 10.1002/cne.902430102pmid: 2869065
We surveyed retinas of Raja erinacea, Mustelus canis, and Squalus acanthias for neurotransmitter substances by using antisera directed against the substances themselves or against their synthesizing enzymes. Both the peroxidase‐antiperoxidase (PAP) and indirect fluorescent techniques were employed to visualize the primary antisera. In all three species positive results were obtained with antisera directed against tyrosine hydroxylase (TOH), glutamic acid decarboxylase (GAD), serotonin (5‐HT), and leucine enkephalin (Lenk). Antisera directed against glucagon, neurotensin, beta‐endorphin, vasoactive intestinal peptide, or bombesin failed to show any specific staining.
Krukoff, Teresa L.; Ciriello, John; Calaresu, Franco R.
doi: 10.1002/cne.902430103pmid: 2869066
The distribution of somatostatin‐like immunoreactivity (SS) was studied in the spinal cord of untreated cats and of cats that had received colchicine at all levels of the cord. In the dorsal horn small (less than 15 μm in diameter), round neurons were found in Rexed laminae II and III at all levels. At all levels laminae IV‐VI contained smaller numbers of immunoreactive neurons that were medium (between 15 and 25μm in diameter) to large (greater than 25μm in diameter) in size. In addition small numbers of medium‐sized neurons were observed at the dorsal and dorsomedial borders of the gray and white matter in segments C1‐5. In the sacral cord (Sl‐3), a group of medium‐sized bipolar neurons was found in the dorsolateral funiculus. In transverse sections the processes of the neurons in these two latter groups travelled in a direction parallel to the border of the gray and white matter. In the intermediate and central gray matter, in addition to the immunoreactive neurons found in the region of the intermediolateral nucleus and nucleus intercalatus of lamina VII in segments C8 to L4 (Krukoff et al., '85a), lamina VII contained immunoreactive neurons at all levels with the largest number occurring in the thoracic cord. These neurons were medium to large in size and were generally multipolar with processes travelling in all directions. Multipolar small immunoreactive neurons were also found in the central gray region (lamina X) in the thoracic and upper lumbar cord. Finally, small numbers of neurons containing SS were found in the ventral horn of the cervical and upper thoracic cord. These multipolar neurons were medium to large in size. The distribution of nerve terminals and fibers containing SS was similar to that previously described in mice, rats, guinea pigs, and primates. Although the function of somatostatin in the spinal cord is not known, its presence in neurons with short processes suggests that it may act to modify local activity in the regions where it is found, including areas involved in sensory, visceromotor, and motor functions.
Morgan, C.; de Groat, W. C.; Nadelhaft, I.
doi: 10.1002/cne.902430104pmid: 3950078
The spinal distribution of sympathetic preganglionic neurons (PGN) and visceral primary afferent neurons sending axons into the hypogastric nerve of the cat has been studied with HRP tracing techniques. After application of HRP to the cat hypogastric nerve, labeled PGN were identified in segments L2‐L5. Most of these neurons were oriented transversely and were divided approximately equally between two nuclei: the principal, nucleus and the intercalated nucleus. Cells were distributed in clusters at 160‐361‐μm intervals along the length of the cord. Sensory neurons were labeled in dorsal root ganglia from T12 to L5. Central axons of these visceral afferents were observed in the medial half of Lissauer's tract from T13 to L7. Afferent axon collaterals extended through lamina I on both sides of the dorsal horn but were most prominent on the lateral side, where they continued into lateral lamina V and VII, often overlapping the dorsal dendrites of PGN in this region. Labeled afferent projections exhibited a periodic distribution in lamina I with clusters of axons occurring at 235‐343‐μm intervals in the rostrocaudal axis. The central projection of hypogastric nerve primary afferents was qualitatively similar to the distribution of visceral afferent projections at other levels of the spinal cord.
Redburn, Dianna A.; Madtes, Paul
doi: 10.1002/cne.902430105pmid: 2419366
Light and electron microscopic autoradiography demonstrates that 3H‐GABA is accumulated by horizontal cells in neonatal rabbit retina but not in the adult. A specific population of horizontal cells appears to be mature at birth and they avidly accumulate 3H‐GABA during a 15‐minute incubation period in vitro. Uptake into horizontal cells is not observed after the fifth postnatal day; 3H‐GABA‐accumulating horizontal cell bodies and their processes are the first identifiable components that clearly mark the future location of the outer plexiform layer at birth and as such, may be considered pioneering elements. Our observations raise the interesting possibility that the pioneering horizontal cell may provide structural and/or chemical factors necessary for the subsequent development of the outer plexiform layer of the retina.
Frotscher, Michael; Léránth, Csaba
doi: 10.1002/cne.902430106pmid: 2419367
A monoclonal antibody against choline acetyltransferase (ChAT), the acetylcholine‐synthesizing enzyme, was used to study cholinergic synagses on identified (Golgi stained) granule cells in the rat fascia dentata. Choline acetyltransferase immunocytochemistry was applied to 40‐μm Vibratome sections cut perpendicular to the longitudinal axis of the hippocampus. Light microscopy revealed fine varicose ChAT‐immunoreactive axons in all layers of the fascia dentata, i.e., in the stratum moleculare, the stratum granu‐losum, and the subgranular polymorph zone. Most fibers were observed in the vicinity of granule cell bodies where they ran mainly parallel to the granular layer. Next, the immunostained Vibratome sections were sandwiched between small pieces of Parafilm and piled to form a block that was covered with agar and Golgi stained. After that, the sections were separated by cutting away the agar and removing the Parafilm. Sections containing well‐impregnated granule cells were gold‐toned (Fairén et al., '77), embedded in Araldite, and subjected to ultrathin sectioning for electron microscopy. A total of 14 gold‐toned granule cells were examined in the electron microscope for synaptic contacts with cholinergic afferents. Choline acetyltransferase‐immunoreactive axon terminals were observed that established symmetric synaptic contacts with the cell bodies and dendritic shafts of the gold‐toned identified granule cells. Two types of contact were observed on spines arising from gold‐toned granule cell dendrites. Immunoreactive terminals established asymmetric synaptic contacts with the head of small spines and symmetric contacts with the stalk of large, complex spines. The boutons forming asymmetric synaptic contacts with the cup‐shaped spine head of the complex spines were not found to be immunoreactive. Our results demonstrate that cholinergic fibers to the rat fascia dentata establish characteristic types of synaptic contact with different postsynaptic elements of granule cells, suggesting a complex function of this afferent system.
Torigoe, Yasuhiro; Blanks, Robert H. I.; Precht, Wolfgang
doi: 10.1002/cne.902430107pmid: 3512624
The nucleus reticularis tegmenti pontis (NRTP) is a precerebellar reticular nucleus that has been found to be related to cerebropontocerebellar pathways and, more recently, to eye movements. The present study investigates the cytoarchitecture, the topography, and the cerebral cortical projections to the NRTP in the pigmented rat. The cytoarchitecture and topography of the NRTP was determined by examination of Nissl‐stained material sectioned in the transverse and sagittal planes. Two cytoarchitectonically distinct portions of the NRTP are apparent; a central subdivision (NRTPc) composed of large multipolar, small spherical, and fusiform neurons, and a pericentral subdivision (NRTPp) composed of loosely packed small fusiform and spherical neurons. The NRTPc is located dorsal to the medial lemniscus and pyramidal tracts over the caudal two‐thirds of the pons. It extends caudodorsally to the region just rostral and ventral to the abducens nucleus. The NRTPp is adjacent to the lateral margins of the NRTPc, rostrally, and lies ventral to the caudal portions of the NRTPc. Large injections of horseradish peroxidase (HRP) were made into the cerebellum in order to determine the degree to which each subdivision of the NRTP contributes to the cerebellar projection. A high percentage of NRTPc neurons and a lower percentage of NRTPp neurons were labeled. These differences in labeling density and neuronal morphology noted above confirm the appropriateness of subdividing the NRTP into central and pericentral subdivisions.
Torigoe, Yasuhiro; Blanks, Robert H. I.; Precht, Wolfgang
doi: 10.1002/cne.902430108pmid: 3512625
The subcortical nuclear groups projecting to the nucleus reticularis tegmenti pontis (NRTP) were studied in pigmented rats with the aid of the retrograde horseradish peroxidase (HRP) technique. Small iontophoretic injections of HRP were placed in the medial regions of the NRTP, an area that has been shown in several species to be involved in eye movements. Other large injections in the NRTP or small injections placed just outside the nucleus were used to clarify the projections to the NRTP. Results indicate that the NRTP receives afferents from (1) visual relay nuclei, including the nucleus of optic tract, the superior colliculus, and the ventral lateral geniculate nucleus; (2) oculomotor‐associated structures including the zona incerta, the H1 and H2 fields of Forel, the nucleus subparafasciculus, the interstitial nucleus of Cajal, the visual tegmental relay zone of the ventral tegmental area of Tsai, the mesencephalic, pontine, and medullary reticular formations, the nucleus of the posterior commissure, and a portion of the periaqueductal gray termed the supra‐oculomotor periaqueductal gray; (3) cerebellar and pontomedullary nuclei, including the superior, lateral, and medial vestibular nuclei, the deep cerebellar nuclei, and NRTP interneurons, and (4) nuclei related to limbic functions including the lateral habenula, the mammillary nuclei, the hypothalamic nuclei, the preoptic nuclei, and the nucleus of diagonal band of Broca.
Goffinet, A. M.; Daumerie, Ch.; Langerwerf, B.; Pieau, C.
doi: 10.1002/cne.902430109pmid: 3950076
Histogenesis was studied in forebrain cortical areas of two reptiles, Emys orbicularis and Lacerta trilineata, by using tritiated thymidine autoradiography. Four areas were considered: the dorsomedial, the general (dorsal), and the lateral cortices, and the dorsal ventricular ridge (DVR). The bulk of neurogenesis in these four pallial fields proceeds within a short period of 8‐9 days, between developmental stages 15 and 18 in Emys and stages 32‐34 in Lacerta. Lateral‐to‐medial as well as anterior‐to‐posterior tangential gradients of histogenesis are present in both species. Radial neurogenetic gradients are directed from outside to inside, except in the medial cortex of lizards, where no radial gradient is seen. This pattern of histogenesis in the cortex of turtles and lizards is comparable to that in mammals in terms of timing and tangential, areal variations. It might represent a “common denominator” of cortical histogenesis. However, in contrast to the mammalian cortex, which develops according to an inside to outside, “inverted” pattern, radial neurogenesis in the cortex of turtles and lizards follows an outside‐to‐inside gradient. These observations suggest that the inside‐out gradient of cortical neurogenesis has been acquired during evolution of the synapsid radiation from stem reptiles to mammals, and that it may be related to the development of radial cortical architectonics.
Morrison, John H.; Foote, Stephen L.
doi: 10.1002/cne.902430110pmid: 3950077
Antisera directed against human dopamine‐ß‐hydroxylase and against serotonin were used to characterize the noradrenergic (NA) and serotoninergic (5‐HT) innervation of several cortical and subcortical visual areas in squirrel monkey (Saimiri sciureus) and cynomolgus monkey (Macaca fascicularis). Few species differences were observed for either monoamine. Cortical areas 17 and 18, as well as visual areas in the temporal and parietal lobe were found to exhibit regional specialization of both 5‐HT and NA innervation. Precisely at the border between areas 17 and 18, the laminar innervation patterns and density characteristic of NA fibers in area 17 (Morrison et al., '82a; Kosofsky et al., '84) shift so that layer IV of area 18 contains more fibers than layer IV of area 17, and the overall density of fibers in area 18 is higher. For 5‐HT, the highly laminated patterns characteristic of area 17 (Morrison et al., '82a; Kosofsky et al., '84) also observe this cytoarchitectonic boundary. Fibers in area 18 are more evenly distributed across laminae, and the overall density of fibers decreases. The visual region of the inferotemporal cortex was found to be very lightly innervated by NA fibers and very densely innervated by 5‐HT fibers. Area 7 of the parietal lobule was more densely innervated by NA fibers, and less densely innervated by 5‐HT fibers, than any other visual cortical region examined.
Showing 1 to 10 of 10 Articles