bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence to support the distal vagal ganglion as the origin of C cells of the ultimobranchial gland in the chick
Authors: Kameda Yoko 
Published: January 2005

AbstractFormation and development of the ultimobranchial anlage were studied in chicken embryos by immunohistochemistry with the antibodies to class III β‐tubulin, TuJ1, human leukemic cell‐line (HNK‐1), and protein gene product (PGP) 9.5, all of which recognized neurons. Medial to the fourth aortic arch, the ultimobranchial anlage was formed by the extension of the ventral portion of the fourth pharyngeal pouch at 4. 5 days of incubation. At 5 days of incubation, TuJ1—immunoreactive cells with long cell processes began to enter the ultimobranchial anlage, which displayed a follicle structure. At 6 days of incubation, numerous neuronal cells that were continuos with the distal vagal ganglion (nodose ganglion) and expressed immunoreactivity for TuJ1, HNK‐1, and PGP 9. 5 were found to be in direct contact with the peripheral portion of ultimobranchial anlage. The TuJ1 antibody reacted only with the neuronal cells, whereas the HNK‐1 and PGP 9. 5 antibodies reacted with both endodermal epithelial cells and the neuronal cells in the ultimobranchial anlage. Subsequently, the ultimobranchial anlage rapidly increased in size; the follicle wall was thickened and a central cavity disappeared. The TuJ1—immunoreactive cells were distributed throughout the ultimobranchial parenchyma in 7‐day‐old embryos. The neuronal cell streams from the distal vagal ganglion to the ultimobranchial anlage were still prominent at 8 days of incubation. Almost all parenchymal cells of the ultimobranchial glands were intensely immunoreactive for TuJ1, HNK‐1 and PGP 9. 5 between 10 and 16 days of incubation. These results indicate that the neuronal cells from the distal vagal ganglion enter into the ultimobranchial anlage and give rise to C cells, i.e., C cells differentiate along the neuronal lineage. During embryonic development, C cells of the chick ultimobranchial glands transiently express a number of neuronal properties. © 1995 Wiley‐Liss, Inc.
Presynaptic metabotropic glutamate receptors in adult and developing neurons: Autoexcitation in the olfactory bulb
Authors: van den Pol Anthony N. 
Published: January 2005

AbstractThe mitral cell of the olfactory bulb is the primary relay neuron that transmits information from the olfactory receptors to the rest of the brain. This excitatory neuron releases glutamate from presynaptic dendrites and axon terminals. All rat mitral cells studied showed strong, selective, and widespread metabotropic glutamate receptor mGluR1α immunoreactivity on the presynaptic membrane of dendrites, often at the synaptic vesicle release site, when examined with light and electron microscopy. The finding of glutamate receptors on mitral cell secondary dendrites supports the conclusion that not all dendritic membrane with glutarnate receptors necessarily have gray type I asymmetrical synaptic specializations. In contrast, the metabotropic glutamate receptor mGluR5 was not found in mitral cells but was expressed by granule cells and astrocytes around mitral dendrites.Both mGluR1α and mGluR5 were expressed early in development, with strong immunostaining present by postnatal day 1. MGluR1α staining at birth mirrored the adult staining pattern. MGluR5 staining at birth showed different patterns of immunostaining than that found in the adult, particularly in the external plejdform layer. In vitro olfactory bulb neurons and their dendrites from embryonic day (E) 18 olfactory bulbs responded to t‐ACPD and quisqualate, selective and fionselective metabotropic glutamate receptor agonists, and to several ionotropic glutamatel agonists with increases in intracellular Ca2+ as studied with fura‐2 digital imaging. These data indicate that the receptors were functionally active at an early stage of development. Application of the glutarnate receptor blockers d‐2‐amino‐5‐phosphonovalerate (AP5) and 6‐cyano‐7‐nitroquinoxaline (CNQX) to E17 olfactory bulb neurons after only 4 days in vitro resulted in a dramatic decrease in Ca2+ levels in 70% of 128 cells tested, suggesting that embryonic neurons after a short time in vitro can actively secrete glutamate.The presence of glutamate receptors on the long mitral cell dendrite suggests that it would be able to respond to release of its own excitatory transmitter, probably at an early stage of development. In the probable absence of other excitatory input to the secondary mitral dendrites, it would be the only excitatory “input.” This autoexcitatory response would be modulated by release of GABA from olfactory interneurons occurring milliseconds after glutamate release induced by olfactory nerve activation. This novel type of neuronal microcircuitry would potentially amplify signal transmission and current spread along the long mitral dendrites and could play an important role in lateral inhibition of olfactory neurons. © 1995 Wiley‐Liss, Inc.
Expression of glial fibrillary acidic protein and its relation to tract formation in embryonic zebrafish (Danio rerio)
Authors: Marcus Riva C. , Easter Stephen S. 
Published: January 2005

AbstractTo address possible roles of glial cells during axon outgrowth in the vertebrate central nervous system, we investigated the appearance and distribution of the glial‐specific intermediate filament, glial fibrillary acidic protein (GFAP), during early embryogenesis of the zebrafish (Danio rerio). Immunopositive cells first appear at 15 hours, which is at the time of, or slightly before, the first axon outgrowth in the brain. Immunopositive processes are not initially present in a pattern that prefigures the location of the first tracts but rather are distributed widely as endfeet adjacent to the pia, overlying most of the surface of the brain with the exception of the dorsal and ventral midline. The first evidence for a specific association of immunopositive cells with the developing tracts is observed at 24 hours in the hindbrain, where immunopositive processes border axons in the medial longitudinal fasciculus. By 48 hours, immunopositive processes have disappeared from most of the subpial lamina and are found exclusively in association with tracts and commissures in three forms: endfeet, radially oriented processes, and tangentially oriented processes parallel to axons. This last form is particularly prominent in the transverse plane of the hindbrain, where they define the boundaries between rhombomeres. These results suggest that glial cells contribute to the development and organization of the central nervous system by supporting early axon outgrowth in the subpial lamina and by forming boundaries around tracts and between neuromeres. The results are discussed in relation to previous results A neuron‐glia interactions and possible roles of glial cells in axonal guidance. © 1995 Wiley‐Liss, Inc.
Acute exposure to alcohol during early postnatal life causes a deficit in the total number of cerebellar Purkinje cells in the rat
Authors: Pauli J. , Wilce P. , Bedi K. S. 
Published: January 2005

AbstractAlcohol taken regularly over a lengthy period of time has been claimed to cause to loss of neurons in both the adult and developing brain. However, it remains uncertain whether acute, as opposed to chronic, exposure to alcohol at specified periods can also cause disruption in the neuronal population of the developing brain. This question was investigated by exposing Wistar rat pups to 7.5 g/kg body weight of ethanol administered as a 10% solution via an intragastric cannula over an 8 hour period either on the 5th (PND5) or the 10th (PND10) postnatal day of age. Gastrostomy controls received a 5% sucrose solution substituted isocalorically for the ethanol. Another set of pups raised by their mothers was used as “suckle controls”. All surgical procedures were carried out under halothane vapour anaesthesia. After the artificial feeding regimes, all pups were returned to the lactating dams and weaned at 21 days of age. Between 52 and 54 days of age, the rats were anaesthetised with an intraperitoneal injection with Nembutal and killed by intracardiac perfusion with 3% glutaraldehyde in 0.1 M phosphate buffer. The relatively unbiased stereological procedure known as the “fractionator” method was used to estimate the total number of Purkinje cells in the cerebellum of each animal. The Purkinje cell nucleolus was used as the counting unit; it was assumed that each Purkinje cell contained only one nucleolus. PND10 ethanol‐treated rats and gastrostomy and suckle controls had between about 210,000‐232,000 Purkinje cells in the cerebellum. However, the PND5 ethanol‐treated rats had only about 137,000 Purkinje cells. Two‐way analysis of variance procedures revealed significant main effects of age at time of alcohol exposure and groups as well as a significant interaction between them. It is concluded that the Purkinje cell population numbers can be disrupted by acute exposure to alcohol on the 5th, but not the 10th, postnatal day of age. © 1995 Wiley‐Liss, Inc.
Distributions of the mRNAs for L‐2‐amino‐4‐phosphonobutyrate‐sensitive metabotropic glutamate receptors, mGluR4 and mGluR7, in the rat brain
Authors: Ohishi Hitoshi , Akazawa Chihiro , Shigemoto Ryuichi , Nakanishi Shigetada , Mizuno Noboru 
Published: January 2005

AbstractThe distribution of mRNAs for metabotropic glutamate receptors, mGluR4 and mGluR7, which are highly sensitive for L‐2‐amino‐4‐phosphonobutyrate (L‐AP4), was examined in the central nervous system of the rat by in situ hybridization. In general, the hybridization signals of mGluR7 mRNA were more widely distributed than those of mGluR4 inRNA, and differential expression of mGluR4 mRNA and mGluR7 mRNA was clearly indicated in some brain regions. Intense or moderate expression of mGluR4 mRNA was detected in the granule cells of the olfactory bulb and cerebellum, whereas no significant expression of mGluR7 mRNA was found in these cells. In other neurons or regions where mGluR7 mRNA was intensely or moderately expressed, no significant expression of mGluR4 mRNA was observed. Such were the mitral and tufted cells of the olfactory bulb; anterior olfactory nucleus; neocortical regions; cingulate cortex; retrosplenial cortex; piriform cortex; perirhinal cortex; CAl; CA3; granule cells of the dentate gyrus; superficial layers of the subicular cortex; deep layers of the entorhinal, parasubicular, and presubicular cortices; ventral part of the lateral septal nucleus; septohippo campal nucleus; triangular septal nucleus; nuclei of the diagonal band; bed nucleus of the stria terminalis; ventral pallidum; claustrum; amygdaloid nuclei other than the intercalated nuclei; preoptic region; hypothalamic nuclei other than the medial mammillary nucleus; ventral lateral geniculate nucleus; locus coeruleus; Purkinje cells; many nuclei of the lower brainstem other than the superior coUiculus, periaqueductal gray, interpeduncular nucleus, pontine nuclei, and dorsal cochlear nucleus; and dorsal horn of the spinal cord. Both mGluR4 mRNA and mGluR7 mRNA were moderately or intensely expressed in the olfactory tubercie, superficial layers of the entorhinal cortex, CA4, septofimbrial nucleus, intercalated nuclei of the amygdala, medial mammillary nucleus, many thalamic nuclei, and pontine nuclei. Intense expression of both mGluR4 mRNA and mGluR7 mRNA was further detected in the trigeminal ganglion and dorsal root ganglia, whereas no significant expression of them was found in the pterygopalatine ganglion and superior cervical ganglion. The results indicate differential roles of the L‐AP4‐sensitive metabotropic glutamate receptors in the glutarnatergic nervous system. © 1995 Wiley‐Liss, Inc.
Estrogen modulation of mRNA levels for the two forms of glutamic acid decarboxylase (GAD) in female rat brain
Authors: McCarthy M. M. , Kaufman L. C. , Brooks P. J. , Pfaff D. W. , Schwartz‐Giblin S. 
Published: January 2005

AbstractTwo separate forms of glutamic acid decarboxylase, now termed GAD65 and GAD67 are the rate limiting enzymes for synthesis of γ‐aminobutyric acid (GABA). Because of the significance of GABA to neuroendocrine processes, numerous attempts have been made to determine the impact of gonadal steroids on enzyme functioning with inconclusive results. Therefore, we attempted to determine the impact of estradiol on mRNA levels for each form of GAD by quantitative in situ hybridization histochemistry in various brain regions.Ovariectomized rats were treated with estradiol benzoate or oil vehicle on 2 consecutive days and the brains collected on the third day. DNA probes specific for GAD65 or GAD67 were radiolabeled with CTP using asymmetric polymerase chain reaction. Results of in situ hybridizations for each probe on alternate sections from the same animals were analyzed for magnocellular preoptic area (McPOA), dorsal medial nucleus of the hypothalamus (DMN), zona incerta (ZI), and midbrain central gray (MCG). In the McPOA, estradiol exerted opposite effects on the frequency distribution of pixels per cell for the two GAD mRNA probes, significantly increasing GAD65 (P < .05) and decreasing GAD67 (P < .01; Kolmogorov‐Smirnov). In the DMN, estradiol treatment significantly increased GAD67 by 60% (P < .05; two‐way ANOVA) but decreased GAD65 mRNA by 73% (P < .01). Note the direction of effects are opposite between McPOA and DMN. In MCG, analysis showed no estradiol effect on GAD mRNA levels/cell, but the proportion of cells expressing detectable levels of GAD65 or GAD67 increased by 33–40% in estradiol‐treated rats (χ2, P < .001). © 1995 Wiley‐Liss, Inc.
Anatomical basis for interactions of enkephalins with other transmitters in the CNS of a snail
Authors: Dyakonova Varvara , Carlberg Mats , Sakharov Dmitri , Elofsson Rolf 
Published: January 2005

AbstractImmunocytochemical techniques for double staining were employed to investigate the morphological basis for interactions between enkephalins and other neuroactive compounds in the behavior of the gastropod mollusc Cepaea nemoralis. Coexistence of each of the two enkephalins with FMRFamide, serotonin or GABA‐like immunoreactivity was found in certain neurons in cerebral, parietal, and pedal ganglia. Tyrosine hydroxylase‐immunoreactive neurons were occasionally seen in close apposition to, but never colocalized with, the enkephalins. A comparison between these anatomical observations and previous behavioral studies suggests that in gastropod molluscs cotransmission of enkephalins with classical transmitters may, at least partly, reflect synergism of these substances in the control of definite behavioral programs. © 1995 Wiley‐Liss, Inc.
Periventricular morphology in the diencephalon of antarctic notothenioid teleosts
Authors: Lannoo Michael J. , Eastman Joseph T. 
Published: January 2005

AbstractWe have examined the subependymal region of the diencephalic third ventricle in notothenioid perciforms and report a pattern of neuropil expansions that appears to be phyletically derived for notothenioids and their outgroups but that is otherwise unique among vertebrates. We recognize five types of expansions based on their composition (from less dense neuropil to sacs) and width or protrusion into the third ventricle. In the species with the most elaborate morphology,Trematomus bernacchii, bilateral subependymal expansions fuse along the midline to form a single sac within the ventricular cavity. The extent of these expansions loosely corresponds with phyletic position but also (and perhaps more importantly) is correlated with the habitation of cold water (r2= 0.48;P= 0.012). Furthermore, subependymal expansion type is positively correlated with the maximum size of the soma of neurons in two hypothalamic nuclei, the preopticus magnocellularis (r2= 0. 54;P= 0. 006) and the lateralis tuberis (r2= 0.40;P= 0.038). These nuclei project to the pituitary and contain cerebrospinal fluid‐contacting neurons. In considering the functional consequences of this morphology, we cannot dismiss the possibility that these structures form a specialized enteroceptive system tied to the monitoring of cerebrospinal and extracellular fluid components, including antifreeze glycopeptides and inorganic ions. © 1995 Wiley‐Liss, Inc.
Intrinsic connections of the rat amygdaloid complex: Projections originating in the basal nucleus
Authors: Savander Vesa , Go C.‐Genevieve , Ledoux Joseph E. , Pitkänen Asla 
Published: January 2005

AbstractThe amygdaloid complex is involved in associational processes, such as the formation of emotional memories about sensory stimuli. However, the anatomical connections through which the different amygdaloid nuclei process incoming information and communicate with the other amygdaloid nuclei, is poorly understood. As part of an ongoing project aimed at elucidating the intrinsic connections of the rat amygdaloid complex, we injected the antero grade tracer PHA‐L (Phaseolus vulgaris‐leucoagglutinin) into different rostrocaudal levels of the basal nucleus of the amygdala in 21 rats and analyzed the distribution of labeled fibers and terminals throughout the amygdaloid complex. The connectional analysis, together with cytoarchitectonic observations, suggested that contrary to previous notions the basal nucleus in the rat has three divisions: magnocellular, intermediate, and parvicellular. The magnocellular division has heavy reciprocal connections with the lateral portion of the parvicellular division and the intermediate division projects weakly to the parvicellular division, whereas the projection from the medial: portion of the parvicellular division to the intermediate division is heavy and the lateral and medial portions of the parvicellular division are only weakly interconnected, as are the magnocellular and intermediate divisions. The main intraamygdaloid targets of the basal nucleus projections are the nucleus of the lateral olfactory tract, the anterior amygdaloid area, the medial and capsular divisions of the central nucleus, the anterior cortical nucleus, and the amygdalohippocampal area. Our findings provide the most detailed understanding of the intra‐amygdala connections of the basal nucleus to date and show that the connections within the basal nucleus and between the basal nucleus and other amygdaloid areas are more widespread and topographically organized than previously recognized. © 1995 Wiley‐Liss, Inc.
Morphogenetic reorganization of the brain during embryogenesis in the grasshopper
Authors: Boyan George S. , Williams J. Leslie D. , Reichert Heinrich 
Published: January 2005

AbstractWe have studied the morphogenetic reorganization that occurs in the grasshopper brain during embryogenesis. We find that morphogenetic movements occur at three organizational levels during brain development. First, the entire developing brain changes its orientation with respect to the segmental chain of ventral ganglia. A 90° shift in the attitude of the brain neuraxis occurs during embryogenesis due to a gradual upward movement of the cerebral structures in the head. Second, the clusters of proliferating neuroblasts and progeny that generate the neuroarchitecture of the mature brain move relative to one another and to nonneural structures such as the stomodeum. This is especially pronounced for the pars intercerebralis and for the tritocerebrum, as shown by annulin and engrailed immunoreactivity. Third, individual neuroblasts within a given proliferative cluster undergo positional reorganization during embryogenesis. Identified neuroblasts of the tritocerebrum and the pars intercerebralis are displaced within the brain. We conclude that the transformation of the simple sheet‐like structure of the early embryonic brain into the highly differentiated structure of the mature brain involves a series of morphogenetic movements that occur in virtually all parts of the brain. © 1995 Wiley‐Liss, Inc.
Plasticity of mature sensory cerebrovascular axons following intracranial infusion of nerve growth factor
Authors: Isaacson Lori G. , Ondris D. , Crutcher K. A. 
Published: January 2005

AbstractMature perivascular sympathetic axons associated with the intradural segment of the internal carotid artery (ICA) of the adult rat respond by sprouting following a two week infusion of nerve growth factor (NGF) into the lateral ventricle of the brain. Because nonsympathetic axons such as those comprising the sensory and parasympathetic population have been shown to respond to NGF, the present study was carried out to determine whether mature sensory axons respond to in vivo NGF infusion and whether competitive interactions between the innervating populations might affect the responsiveness of these axons to NGF. Standard electron microscopic techniques as well as calcitonin‐gene‐related peptide (CGRP) immunohistochemistry at the light microscopic level were used to examine the effects of intracerebroventricular NGF infusion on mature perivascular fibers with and without prior sympathetic denervation (i. e., bilateral superior cervical ganglionectomy). Following NGF infusion, CGRPimmunoreactive fibers appeared thicker and more numerous in the longitudinal plane when compared with vehicle controls. However, at the ultrastructural level, a significant increase in the total number of axons was not observed, although there was an increase in the number of large granular vesicles, suggesting that the CGRP fibers responded to exogenous NGF with an increase in neurotransmitter content, but not by sprouting. Sympathetic denervation, on the other hand, resulted in a significant increase in the number of fibers passing in the circumferential plane. The most dramatic change in CGRP immunoreactivity was observed following combined sympathetic denervation and subsequent NGF infusion, where, in addition to the presence of thicker immunoreactive fibers, a significant increase in the perivascular density of immunoreactive fibers associated with the intradural blood vessels was observed. These findings suggest that exogenous NGF has different effects on mature sympathetic and nonsympathetic fibers that innervate intradural blood vessels. The former exhibit robust sprouting, whereas the latter do not sprout in response to NGF but show evidence for increased neuropeptide content. In addition, the heightened response by sensory axons following denervation and subsequent NGF infusion provides support for the idea that sensory and sympathetic axons normally compete for target space and/or target‐derived neurotrophic factors. © 1995 Wiley‐Liss, Inc.