bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cerebellar Purkinje cells from the Lurcher mutant and wild‐type mouse grown in vitro: A light and electron microscope study
Authors: Doughty Martin L. , Patterson Lilian , Caddy Keith W. T. 
Published: January 2005

AbstractLurcher is an autosomal semidominant murine mutation. Lurcher heterozygotes, (+/Lc) lose all their cerebellar Purkinje cells by adulthood. Explants from 2 days postnatal (P2) wild‐type (+/+) and +/Lc cerebellar cortex were grown in vitro to investigate the role of local neuronal environment and afferent input on the degenerating +/Lc Purkinje cell. In Lurcher explants, Purkinje cells were maintained for up to 25 days in vitro. No significant difference was observed between +/+ and +/Lc Purkinje cell numbers from 10 to 20 days in vitro, as revealed by calbindin‐D immunoreactivity. Growing +/Lc explants in association with + / + explants resulted in no significant difference in Purkinje cell survival (10–20 days in vitro). Image analysis of the gross morphology of calbindin‐D‐immunostained Purkinje cells from +/+ and +/Lc explants grown in vitro revealed a significant decrease in the total area and dendritic lengths of +/Lc Purkinje cells (15 and 20 days in vitro). The fine structure of +/Lc and +/+ Purkinje cells was examined under the electron microscope (10–25 days in vitro). No difference in ultrastructure was observed between +/Lc and +/+ Purkinje cells grown in vitro, and many features similar to normal Purkinje cell development in vivo were present. These included monosynaptic parallel fibre synapses with Purkinje cell dendritic spines, other interneuron synapses with Purkinje cell dendrites and soma, astroglial investment, and minimal extracellular space in the neuropil. Unusual features observed included a persistence of the perisomatic spines in some Purkinje cells, an absence of Nissl bodies in the Purkinje cell perikaryon, naked Purkinje cell dendritic spines, and occasional heterol, ogous synapses. The results are discussed in the light of previous chimeric analysis of the Lurcher mutation, and a hypothesis is put forward to explain the survival of + /Lc Purkinje cells in vitro. © 1995 Wiley‐Liss, Inc.
Nitric oxide‐synthesising neurons in the central subnucleus of the nucleus tractus solitarius provide a major innervation of the rostral nucleus ambiguus in the rabbit
Authors: Gai W.‐P. , Messenger J. P. , Yu Y.‐H. , Gieroba Z. J. , Blessing W. W. 
Published: January 2005

AbstractWe describe an intramedullary nitric oxide synthase (NOS) neural pathway that projects from the nucleus tractus solitarius (NTS) to the rostral nucleus ambiguus (NA) in the rabbit. With the use of NADPH diaphorase histochemistry and NOS immunohistochemistry, a compact group of NOS‐positive perikarya was identified in the central subnucleus of the NTS dorsomedial to the tractus solitarius and rostral to the obex. A dense network of NOS terminals was seen in the rostral NA. We investigated whether NOS terminals in the NA derive from NOS perikarya in the central NTS and whether the central NOS pathway links esophageal afferents and efferents. In some rabbits, the central NTS was unilaterally lesioned. In others, Phaseolus vulgaris‐leucoagglutinin (PHA‐L) was injected into the central NTS, or cholera toxin‐gold was injected into the NA, or cholera toxin‐horseradish peroxidase (HRP) was injected into the wall of the esophagus. The medulla was subsequently processed to demonstrate PHA‐L, cholera toxin‐gold, HRP, and NOS reactivity. Seven days after the NTS lesion, we observed a marked decrease in the density of NOS terminals in the ipsilateral NA. After injection of PHA‐L into the central NTS, a dense group of PHA‐L fibres was seen in the rostral NA, principally ipsilaterally. Afferent fibres from the esophagus were found around the NOS cell bodies in the central NTS, and many of these NOS neurons were double labeled with cholera toxin‐gold after injection of this tracer into the NA. NOS terminals were found around NA neurons that were retrogradely labelled from the esophagus. We conclude that the NOS neurons in the central NTS act as interneurons in a central pathway connecting esophageal afferents and efferents. © 1995 Wiley‐Liss, Inc.
Different climbing fibres innervate separate dendritic regions of the same purkinje cell in hypogranular cerebellum
Authors: Bravin Monica , Rossi Ferdinando , Strata Piergiorgio 
Published: January 2005

AbstractElectrophysiological experiments have shown that in hypogranular cerebella the Purkinje cells are innervated by several climbing fibres. The aim of this paper is to provide morphological evidence for this multiple innervation and to describe the topographical distribution of the different climbing fibres onto the somadendritic region of the Purkinje cell.Experiments have been performed in hypogranular adult Wistar rats lesioned during the first postnatal week by methylazoxymethanol (MAM) or by X‐irradiation. Purkinje cells were labelled by an anti‐calbindin antibody, whereas climbing fibres were visualised by means of Phaseolus vulgaris leucoagglutinin.Purkinje cells showed variable degrees of abnormality and displacement. Climbing fibres made contact with the dendrites of all kinds of Purkinje cells, including those ectopically positioned whose dendrites branched in the white matter. This shows that Purkinje cells can develop dendritic branching in the absence of granule cells and maintain the capability of interacting with their proper afferents, even when they are severely affected and displaced. In four Purkinje cells we have been able to follow the course of two climbing fibre terminal arbourisations. Almost no terminal branches were present around the Purkinje cell soma, and the whole arbour covered the proximal two‐thirds of the Purkinje cell dendritic tree. These arbourisations, after an initial common course along the primary dendrite, distributed to separate dendritic regions. The observation of a single labelled climbing fibre covering a limited region of the dendritic tree was more common. As this finding is never observed in control material, it is concluded that the remaining region is covered by another unlabelled climbing fibre belonging to a different inferior olive neurone.These results represent a morphological demonstration of multiple climbing fibre innervation of the adult Purkinje cell. The maintenance of polyinnervation in the adult, which is consequent to the loss of granule cells, is not associated with a defect in the peridendritic translocation of the olivary arbour. In addition, the strict segregation of the different climbing fibres to distinct territories of the Purkinje cell dendritic tree suggests that each terminal arbourisation acts as a functionally independent unit and prevents other competitors from invading its own target domain. © 1995 Wiley‐Liss, Inc.
Effect of vibrissae deprivation on follicle innervation, neuropeptide synthesis in the trigeminal ganglion, and S1 barrel cortex plasticity
Authors: Li Xinren , Glazewski Stanislaw , Lin Xiaoqln , Elde Robert , Fox Kevin 
Published: January 2005

AbstractDeprivation of vibrissae from an early age causes plasticity in S1 barrel cortex. This method of deprivation is most likely to induce plasticity by altering the balance of primary afferent activity from the deprived and spared vibrissae. To study whether or not induction or expression of this type of plasticity might be affected by follicle nerve injury caused by the deprivation technique, three different methods of detecting nerve injury were used: counting axon numbers in the distal follicle nerve, quantifying morphological changes in axons, and measuring neuropeptide expression in the trigeminal ganglion cells. First, nerves innervating follicles chronically deprived of vibrissae from birth had the same number of myelinated and unmyelinated axons as nerves from normally reared animals. Second, axons innervating deprived follicles showed no morphological changes in myelination or mitochondria characteristic of damaged nerves. Third, the corresponding nerve cell bodies in the trigeminal ganglion did not show upregulation of galanin or neuropeptide Y expression. In contrast, animals receiving mild injury of the follicle nerve endings (by cauterization of the follicle) showed profound changes in axonal myelination and mitochondria and increases in neuropeptide expression. These results imply that vibrissae deprivation does not act by inducing injury of the follicular nerve, suggesting that changes in the balance of follicle nerve activity are the cause of cortical plasticity. Consistent with this notion, a fourth experiment demonstrated that trimming the vibrissae induces cortical plasticity comparable to that induced by complete vibrissae removal. © 1995 Wiley‐Liss, Inc.
The organization of the turtle inner retina. II. Analysis of color‐coded and directionally selective cells
Authors: Ammerüller Josef , Muller Jay F. , Kolb Helga 
Published: January 2005

AbstractColor coding and directional selectivity (DS) of retinal neurons were studied in the Pseudemys turtle by using similar intracellular recording and staining techniques as in the preceding paper (J. Ammermüller and H. Kolb, 1995, J. Comp. Neurol. 358:1–34). Color‐coded responses were elicited by red (621 or 694 nm), green (525 or 514 nm), and blue (455 nm) light flashes. In addition to red/green and yellow/blue types of chromaticity horizontal cells, in our sample of 305 identified cells we found that 17% of bipolar cells, 6.5% of amacrine cells, and 18% of ganglion cells exhibit color‐coded responses. DS responses were found in 37% of the tested ganglion cells and 41% of the tested amacrine cells.Two morphologically identified bipolar cell types, B10 and B11, were red‐ON/blue‐OFF and red‐OFF/green, blue‐ON, respectively. Of five identified amacrine cell types, three were red‐OFF blue‐ON center (Al, A3, A23b), one was red‐OFF/green‐ON center (A32), and one (A33) was double color‐opponent of red‐ON/blue‐OFF center: red‐OFF/blue‐ON surround. Five ganglion cell types had variously color‐coded centers (G14 and G24) or surrounds (G3 and G18), including one type, G6, that was double color‐opponent (red‐OFF/green‐ON center:red‐ON/ green‐OFF surround). Responses to colors were found primarily in the sustained responses of bipolar and ganglion cells. However, in amacrine cells, transient components of the response also showed color dependence. Red‐OFF‐center responses were found in ganglion cells that were in a position to make connections at the strata 2/3 border with the red‐OFF bipolar cell (B11); red‐ON‐center responses occurred in ganglion cells with branches in stratum 4 of the IPL where the red‐ON‐center bipolar (B10) ended. Blue‐ON‐center signals appeared to be processed mainly in strata 1–2/3, and blue‐OFF‐center signals in strata 3–5 of the IPL, with contributions of amacrine cells and bipolar cells.Labeled DS amacrine cells could be identified as A9, A20, and A22, and ganglion cells as G19, G20, and G24. The latter type (G24) showed DS and color coding. All response types (ON‐center, OFF‐center, ON‐OFF) were encountered, DS amacrine cells were monostratified near the middle of the IPL, whereas DS ganglion cells were mono‐, bi‐, and multistratified, although all DS ganglion cells had one feature in common: they had dendrites in stratum 1 of the IPL. We discuss our findings in terms of the importance of color and motion discrimination tasks associated with complex ganglion cell physiology in the retina of this species. © 1995 Wiley‐Liss, Inc.
Inositol 1,4,5‐trisphosphate receptors: Immunocytochemical localization in the dorsal cochlear nucleus
Authors: Ryugo D. K. , Pongstaporn T. , Wright D. D. , Sharp A. H. 
Published: January 2005

AbstractIn the cochlear nucleus of mammals, the relatively homogeneous responses of auditory nerve fibers are transformed into a variety of different response patterns by the different classes of resident neurons. The spectrum of these responses is hypothesized to depend on the types and distribution of receptors, ion channels, G proteins, and second messengers that form the signaling capabilities in each cell class. In the present study, we examined the immunocytochemical distribution of the inositol 1,4,5‐trisphosphate (IP3) receptor in the dorsal cochlear nucleus to better understand how this second messenger might be involved in shaping the neural signals evoked by sound.Affinity‐purified polyclonal antibodies directed against the IP3 receptor labeled a homogeneous population of neurons in the dorsal cochlear nucleus of rats, guinea pigs, mustache bats, cats, New World owl monkeys, rhesus monkeys, and humans. These cells were all darkly immunostained except in the human where the labeling was less intense. Immunoblots of dorsal cochlear nucleus tissue from the rat revealed a single band of protein of molecular weight ∼260 kD, which is the same size as the purified receptor, indicating that our antibodies reacted specifically with the IP3 receptor. These immunolabeled neurons were identified as cartwheel cells on the basis of shared characteristics across species, including cell body size and distribution, the presence of a highly invaginated. Nucleus, and a well‐developed systain of cisternae. Reaction product was localized along the membranes of rough and smooth endoplasmic reticulum, subsurface cisternae, and the nuclear envelope. This label was distributed throughout the cartwheel cell body and dendritic shafts but not within dendritic spines, axons, or axon terminals. The regular pattern of immunolabeling across mammals suggests that IP3 and cartwheel cells are conserved in evolution and that both play an important but as yet unknown role in hearing. © 1995 Wiley‐Liss, Inc.
Developmental time course of acidic and basic fibroblast growth factors' expression in distinct cellular populations of the rat central nervous system
Authors: Kuzis Karl , Reed Susan , Cherry Nicola J. , Woodward William R. , Eckenstein Felix P. 
Published: January 2005

AbstractAcidic and basic fibroblast growth factors (aFGF and bFGF, respectively) are expressed in high levels in adult central nervous system (CNS). We report the time course of developmental appearance and distribution of these factors and of two FGF receptors, FGFR‐1 and FGFR‐2, in the CNS of rats ranging in age from embryonic day 16 to adult. Immunohistochemical analysis showed that sensory neurons in the midbrain were the first cells to contain detectable aFGF immunoreactivity at embryonic day 18. The next cell group to contain aFGF were motor neurons, which were found to be aFGF‐positive at the day of birth. A number of other subcortical neuronal populations were observed to contain aFGF immunoreactivity after postnatal day 7. Adult levels and distribution patterns of aFGF were reached in all CNS areas by postnatal day 28. Basic FGF immunoreactivity was observed at postnatal day 0 in neurons in the CA2 subfield of hippocampus. Astrocytes contained detectable bFGF immunoreactivity, starting at postnatal day 7. Adult levels and patterns of distribution of bFGF were reached in all CNS areas by postnatal day 28. These immunohistochemical observations were confirmed by using bioassay and Western blot techniques. FGFR‐1 and FGFR‐2 mRNA were expressed in significant levels in all CNS areas at all time points analyzed. The observation that aFGF and bFGF appear in specific and distinct cellular populaitions at relatively late developmental times suggests that these FGFs may be involved in spe6ific mechanisms of CNS maturation, maintenance, and repair. © 1995 Wiley‐Liss, Inc.
Sexual and seasonal differences in the vomeronasal epithelium of the red‐backed salamander (Plethodon cinereus)
Authors: Dawley Ellen M. , Crowder James 
Published: January 2005

AbstractSexually dimorphic behaviors often are associated with sexually dimorphic neural structures. Perinatal hormonal levels influence structural sexual dimorphism, and seasonal structural changes also can be the result of seasonal hormonal fluctuations. We compared the volume of vomeronasal organs of male and female red‐backed salamanders (Plethodon cinereus) throughout the year. Odorants are delivered to vomeronasal receptors through nasolabial grooves when salamanders touch the bases of these grooves to objects (nose tapping). Males may locate and identify potential mates through nose tapping during the prolonged breeding season that lasts from October through May. We compared vomeronasal organ data through multiple regression by using total body size, sex, and season as variables that may influence vomeronasal organ volume. Gonads also were examined as an indicator of reproductive status. Total body size and sex significantly affect vomeronasal organ volume; as body size increases, so does vomeronasal organ volume, and males have significantly larger vomeronasal organs than females at all times of the year. During the summer, both males and females have larger vomeronasal organs than at any other time of the year. Summer also is a period of intense foraging and the initiation of a new cycle of gametogenesis. Previous studies of circulating hormone levels in amphibians have shown that the initial stages of gametogenesis correspond to a period of low estradiol and testosterone levels but high gonadotropin‐releasing hormone levels. The functional significance of sexual and seasonal differences in the vomeronasal organs of P. cinereus may relate to the neurogenesis of specialized receptors for courtship and mating. © 1995 Wiley‐Liss, Inc.
Laminar distribution and sources of catecholaminergic input to the optic tectum of the pigeon (Columba livia)
Authors: Rodman Hillary R. , Karten Harvey J. 
Published: January 2005

AbstractA combined immunohistochemical and retrograde tracing approach was used to characterize the catecholaminergic innervation of the optic tectum (TeO), the major target of retinal projections in many avian species. Giemsa counterstaining was employed to determine precisely the laminar localization of immunoreactive fibers and presumptive terminals. The TeO of the pigeon is densely innervated by fibers immunoreactive for tyrosine hydroxylase (TH), which are most heavily distributed to the superficial layers of its dorsal and anterior portions. Within the dorsal‐anterior tectum, TH‐immunoreactive processes are particularly dense in retinorecipient layers 4 and 7 and in layer 5a. As in the mammalian superior colliculus, the bulk of the catecholaminergic innervation of the pigeon TeO reflects inputs, presumably noradrenergic, originating in the locus coeruleus and nucleus subcoeruleus. However, the catecholaminergic innervation of the pigeon TeO shows several features distinct from those reported for the mammalian superior colliculus. These include an input from a pretectal TH‐positive cell group unknown in mammals and the presence of residual TH immunoreactivity after administration of the noradrenergic neurotoxin DSP‐4. Moreover, the pattern of TH‐immunoreactive fibers in pigeon TeO, indicates more laminar and regional specialization within this structure than has been reported for the catecholaminergic innervation of the superior colliculus in mammals. © 1995 Wiley‐Liss, Inc.
Developmental patterning of rod and cone photoreceptors in embryonic zebrafish
Authors: Raymond Pamela A. , Barthel Linda K. , Curran Gary A. 
Published: January 2005

AbstractCone photoreceptors in the zebrafish retina are arranged in a crystalline lattice, with each spectral subtype at a specific position in the array: rod photoreceptors are inserted around the cones. Patterning events and developmental mechanisms that lead to the formation of the cone mosaic are not known. To begin investigating this issue, we examined the initial stages of opsin expression in zebrafish embryos by in situ hybridization with goldfish opsin cRNA probes to determine how and when the cone mosaic pattern arises. We found both differences and similarities in the spatiotemporal patterns of rod and cone development, which suggest the following: (1) Expression of opsin message (including rod opsin, blue and red cone opsins) was initiated at 50–52 hours postfertilization by a few photoreceptors which were consistently found in a ventral patch of retina located nasal to the choroid fissure. (2) The cone mosaic pattern was generated by a crystallization‐like process initiated in the precocial ventral patch and secondarily in nasal retina, which then swept like a wave into dorsotemporal retina. (3) The pattern of differentiation of rods in the ventronasal patch differed substantially from that in the remainder of the retina, suggesting that these precocial rods might differ from typical rods. (4) Developmental maturation of rods in zebrafish, as reflected by expression of opsin, may be accelerated compared to cones, which are thought to become postmitotic before rods. These data are consistent with a model in which lateral inductive interactions among differentiating photoreceptors lead to patterning of the array. © 1995 Wiley‐Liss, Inc.
Platelet‐derived growth factor receptors of mouse central nervous system cells in vitro
Authors: Hutchins James B. 
Published: January 2005

AbstractThis study evaluates the distribution of receptors for platelet‐derived growth factor (PDGF) on central nervous cells maintained in vitro using colloidal gold‐labeled immunocytochemical markers at the electron microscopic level. Platelet‐derived growth factor receptors were found to be sparsely distributed over the surface of type 1 astrocytes, apparent type 2 astrocytes, and neurons. Receptors appeared to be preferentially associated with filopodia‐like extensions of the cell membrane. The existence of functional receptors was confirmed using the impermeant, water‐soluble affinity cross‐linking agent bis(sulfosuccinimidyl) suberate to covalently link radiolabeled PDGF to its receptor. The PDGF/receptor complexes could also be immunoprecipitated with the same antibody used in immunocytochemical experiments. The improved resolution of these techniques allows definitive identification of PDGF receptors on cultured mammalian central nervous system cells other than oligodendrocytes. These data expand the range of possible roles of PDGF during nervous system development. Receptors for PDGF are likely to play a key role in the differentiation of cells in the central nervous system. © 1995 Wiley‐Liss, Inc.