bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential innervation of protruder and retractor muscles of the tongue in rat
Authors: Dobbins Elizabeth G. , Feldman Jack L. 
Published: January 2005

AbstractProtrusion and retraction of the tongue are essential components of such orofacial behaviors as mastication, respiration, and swallowing. Stimulation of the medial branch of the hypoglossal nerve yields tongue protrusion, while stimulation of the lateral branch yields tongue retraction in rat. We exploited the transsynaptic transport capabilities of pseudorabies virus to determine specific circuits that innervate protruder and retractor muscles of the rat tongue. Each group of muscles is innervated by distinct populations of hypoglossal motoneurons: caudal ventral and ventrolateral motoneurons form the largest proportion of those innervating protruders, whereas rostral dorsal motoneurons innervate retractors. Our primary finding was differential innervation of protruder and retractor motoneurons by premotoneurons in the lateral tegmental field: premotoneurons innervating protruder motoneurons were more ventral and ventromedial than those innervating retractor motoneurons. In addition, protruder motoneurons received projections from the ipsilateral lateral parabrachial nucleus but not spinal trigeminal nucleus or medial and ventral subnuclei of the solitary tract; the converse was true for retractor motoneurons. These results suggest segregation of functional networks that control hypoglossal motoneurons. The dorsal medulla, in or around the solitary tract, contains neurons specific to retractor motoneurons, and the region ventrolateral to the hypoglossal nucleus contains circuitry specific to protruder motoneurons. Common innervation of medial and lateral branch motoneurons is provided by premotoneurons in the raphe and gigantocellular reticular formation of the medial medulla. The midline medullary nuclei with diverse projections may coordinate complex behavior or modulate general motoneuron excitability, whereas the lateral reticular formation, with anatomically discrete projections, may control motoneurons that contribute to distinct orofacial behaviors. © 1995 Wiley‐Liss, Inc.
Transplanted human neurons derived from a teratocarcinoma cell line (NTera‐2) mature, integrate, and survive for over 1 year in the nude mouse brain
Authors: Kleppner Sofie R. , Robinson Kathryn A. , Trojanowski John Q. , Lee Virginia M.‐Y. 
Published: January 2005

AbstractRetinoic acid (IRA) induces a human teratocarcinoma cell line (NTera‐2 or NT2) to give rise exclusively to post‐mitotic neuron‐like (NT2N) cells, but NT2N cells never acquire a fully mature neuronal phenotype in vitro. To determine whether NT2N cells can mature into adult neuron‐like cells in vivo, purified NT2N cells were grafted into different regions of the central nervous system (CNS) of adult and neonatal athymic mice, and the grafts were examined immunohistochemically by light, confocal, and electron microscopy using antibodies to a panel of developmentally regulated neuronal polypeptides.NT2N grafts were distinguished from endogenous mouse neurons with antibodies that recognize human or murine specific epitopes in selected neuronal polypeptides. Viable NT2N cells were identified in > 89% of graft recipients (N=90), and some grafts survived 14 months. Within 3 weeks of implantation, grafted NT2N cells re‐extended their processes, and the location of the grafts (e. g., septum versus neocortex) appeared to determine the extent to which processes were elaborated. Within the early post‐transplantation period, grafted NT2N cells expressed the same neuronal polypeptides as their in vitro counterparts. However, between 6 weeks and 4‐6 months post‐implantation, the grafted NT2N cells progressively acquired the molecular phenotype of fully mature in vivo neurons as evidenced by dramatically increased expression of the most highly phosphorylated isoforms of the heavy neurofilament subunit, and the de novo expression of adult CNS tau. Notably, the time course for the extension of processes and the expression of neuronal polypeptides by NT2N grafts was similar in neonatal and adult mice. Although grafted NT2N cells formed synapse‐like structures and elaborated dendrites and axons, these axons remained unmyelinated. Finally, nbne of the transplanted NT2N cells reverted to a neoplastic state.These studies demonstrate that pure populations of grafted human NT2N cells acquire a fully mature neuronal phenotype in vivo, and that these cells integrate and survive for > 1 year post‐implantation in the mouse CNS. These human neuron‐like cells are an attractive model system for studies of neuronal development, polarity and transplantation. © 1995 Wiley‐Liss, Inc.
Human orbitofrontal cortex: Cytoarchitecture and quantitative immunohistochemical parcellation
Authors: Hof Patrick R. , Mufson Elliotf J. , Morrison John H. 
Published: January 2005

AbstractThe primate orbitofrontal cortex is a component of the paralimbic cortical “belt” and consists of several distinct areas. It is involved in high order association functions that include the integration of emotion, behavior, and various sensory processes. To define the cyto‐ and chemo‐architectonic organization of the human orbitofrontal cortex, we have used antibodies to the nonphosphorylated neurofilament triplet protein and to the calcium‐binding proteins parvalbumin and cairetinin. Immunohistochemistry revealed labeling patterns corresponding to the cytoarchitecture defined by Nissi preparations. Neurofilament protein‐immunoreactive pyramidal neurons were located only in layers V–VI in the agranular posterior orbitofrontal cortex, whereas they were distributed in both layers III and V–VI in the anteromedial and anterolateral granular regions. The intermediate dysgranular portion of the orbitofrontal cortex represented a transition zone with a progressive decrease in layer III labeled pyramidal cell numbers posteriorly. The distribution of parvalbumin‐ and cairetinin‐immunoreactive interneurons was more homogeneous, although the posteromedial region and the cortex of the inferior rostral sulcus had slightly lower parvalbumin‐positive neuron counts than the other orbitofrontal areas. Parvalbumin immunoreactivity in the neuropil exhibited a high degree of regional specialization in that it was consistently less intense in the cortex of the intermediate and posterior part of the gyrus rectus, whereas the other orbitofrontal areas had a very dense nei staining in layers III to V. Also, there was a dense plexus of parvalbumin immunoreactive fibers restricted to layer I in the posterolateral orbitofrontal cortex, and patches of neuropil staining in layer III of the inferior rostral sulcus. These region‐specific neuropil staining patterns may correspond to the distribution of parvalbumin‐immunoreactive thalamocortical projections to distinct domains of the orbitofrontal cortex. This regional parcellation of the human orbitofrontal cortex as defined by specific neuronal markers, may represent an anatomical substrate for the localization of the various functions attributed to this poorly understood cortical region. © 1995 Wiley‐Liss, Inc.
NGF‐dependent and NGF‐independent recovery of sympathetic function after chemical sympathectomy with 6‐hydroxydopamine
Authors: Gloster Andrew , Diamond Jack 
Published: January 2005

AbstractTo help clarify the distinction between the nerve growth factor (NGF)‐dependent collateral sprouting of sympathetic nerves and their NGF‐independent regeneration after crush, we used 6‐hydoxydopamine (OHDA) to destroy the sympathetic terminals in adult rats; this leaves the axons damage‐free. Would recovery occur by regeneration and/or collateral sprouting? A single 6‐OHDA injection abolished the sympathetic pilomotor field revealed by electrical stimulation of a cutaneous nerve. Recovery began within 2 days, and by 20 days the field was reestablished. If the field was “isolated” by adjacent denervations at the time of 6‐OHDA treatment, the recovering pilomotor field expanded extensively into the surrounding territory. In the presence of anti‐NGF, however, the pilomotor field expansion ceased at about 60% of its former size; if anti‐NGF treatment was discontinued, expansion recommenced and extended into the surrounding skin. We suggest that the latter, NGF‐dependent, growth phase corresponds to collateral sprouting, and the initial NGF‐independent one to regeneration. After simple nerve crush, however, such regeneration can triple the normal sympathetic field size. This difference between crush‐ and 6‐OHDA‐induced regeneration might relate to the “cell body reaction” (CBR); the CBR is reduced with increasing distance of the lesion and is undetectable after a 6‐OHDA lesion. Since the CBR and the vigor of regeneration are both increased by repeated axonal injury, we tested the effects of multiple 6‐OHDA treatments; this significantly increased the initial NGF‐independent expansion. We hyprthesize that regeneration is regulated largely by mechanisms associated with the CBR, and that neurotrophin‐dependent collateral sprouting occurs independently of these. © 1995 Wiley‐Liss, Inc.
The development of interneurons in the chick embryo spinal cord following in vivo treatment with retinoic acid
Authors: Shiga Takashi , Gaur Vinod P. , Yamaguchi Katsuhiro , Oppenheim Ronald W. 
Published: January 2005

AbstractTo investigate the role of retinoic acid (RA) in the development of interneurons in the spinal cord, we examined the expression of cellular retinoic acid binding protein type I (CRABP I). The earliest developing interneurons in the chick spinal cord can be divided into two major groups: circumferential (C) neurons and primitive longitudinal (PL) neurons. In brachial segments, both types of interneurons began to express CRABP I at stage (st.) 13+ of the V. Hamburger and H.L. Hamilton (1951, J. Morphol. 88:49–92) stage series, which is before the onset of axonogenesis. Subsequently, with the onset of axonal outgrowth, C neurons and PL neurons expressed CRABP I in their cell bodies, axons, and growth cones. The expression of CRABP I was developmentally regulated. CRABP I immunoreactivity gradually decreased after st. 36 (embryonic day [E] 10) such that no interneurons expressed this protein by E21. The transient expression of CRABP I during a period of intensive axonal growth suggested that RA may be involved in the development of interneurons. To test this idea, we implanted an all‐trans RA‐containing ion exchange bead into either rostral segments of the spinal cord at st. 12–13 or into caudal segments at st. 15–16, all stages that are well before the appearance of CRABP‐I‐positive neurons in these segments. In the RA‐treated spinal cord, increased numbers of pyknotic cells were found predominantly in dorsal regions, presumably reflecting the death of neuroepithelial cells, C neurons premigratory neural crest cells. Surviving C neurons in the RA‐treated spinal cord extended their axons ventrally toward the floor plate as in control embryos. PL neurons also projected their axons rostrally or caudally in the RA‐treated spinal cord, similarly to control embryos. However, the proportion of caudally projecting PL neurons was significantly increased in segments rostral to the RA‐containing bead. These results suggest that RA may regulate the survival and axonal orientation (directionality) of subpopulations of spinal interneurons. © 1995 Wiley‐Liss, Inc.
Calretinin immunoreactive structures in the human hippocampal formation
Authors: Nitsch Robert , Ohm Thomas G. 
Published: January 2005

AbstractThe calcium‐binding protein calretinin is present in an intrinsic GABAergic and an extrinsic non‐GABAergic system in the rat and monkey hippocampal formation. Important species differences have been noted in hippocampal cell types immunostained for calretinin and the termination pattern of calretinin containing hypothalamic afferents in the hippocampus. In the present study, calretinin‐containing neurons were visualized using immunocytochemistry in the human hippocampal formation of individuals which showed no significant neuropathological alterations. Calretinin‐immunoreactivity was present exclusively in non‐granule cells of the dentate gyrus and in non‐pyramidal cells of Ammon's horn. Calretinin‐positive neurons were found most frequently in the hilus of the fascia dentata and in strate radiatum and lacunosum‐moleculare of CA1, whereas neurons in CA2 and CA3 were rarely immunostained. The majority of calretinin‐immunoreactive neurons were small, bipolar or fusiform neurons. The dendritic trees of the calretinin‐positive neurons were, for the most part, parallel to the dendrites of the principal cells. In the hilus, however, we observed cells with dendrites restricted to the hilar area. These dendrites were parallel to the granule cell layer. In the stratum lacunosum‐moleculare, neurons with dendrites oriented parallel to the hippocampal fissure were frequently detected. In general, dendrites were smooth or sparsely spiny, displaying small conventional spines. The axons usually emerged from the proximal dendrite and could be followed over long distances. Axons were thin, had small varicosities and displayed only few collaterals which branched relatively far away from the cell body. Distinct bands of darkly stained calretinin‐positive fibers occupied the innermost portion of the dentate molecular layer and the pyramidal cell layer of CA2. This distribution of calretinin‐immunoreactive structures in the human hippocampus is similar to that observed in other primates but differs from that described in lower mammals, i.e., the rat. Our findings suggest that primates may share a common hippocampal calrtinin‐containing system, presumably both the intrinsic GABAergic and the extrinsic hypothalamic non‐GABAergic components. © 1995 Wiley‐Liss, Inc.
Fibroblasts at the transection site of the injured goldfish optic nerve and their potential role during retinal axonal regeneration
Authors: Hirsch Sabine , Cahill Mary Anne , Stuermer Claudia A. O. 
Published: January 2005

AbstractThe region at and around the site of optic nerve transection (ONS) in goldfish, topologically the equivalent of the glial scar in mammals, is reported to remain free of astrocytes over weeks, but its cellular constituents are unknown.To learn what type of cell occupies the site of injury and thus provides support for the rapidly regenerating retinal growth cones, immunostaining experiments at the light micro scopic level and electron microscopic examinations were undertaken. Between 2 and 30 days after ONS, an area up to 150 μm wide at the transection site exhibits intense anti‐fibronectin immunoreactivity. This site contained cells and processes with ultrastructural characteristics of fibroblasts and abundant collagen fibrils. Moreover, on fibroblast cultures derived from regenerating optic nerves, retinal axons grew to considerable density in vitro. Since fibroblasts are constituents of the interfascicular spaces and outer nerve sheath of the normal goldfish optic nerve, the present data imply that fibroblasts of either source migrate into the lesion. Judging from fibronectin immunostaining they remain there during the passage of regenerating axons, and thus may provide physical and perhaps molecular support for axon growth. The fibroblasts are again restricted to interfascicular spaces after restoration of the astrocytic glia limitans around regenerated fascicles. © 1995 Wiley‐Liss, Inc.
Development of neuropeptide Y immunoreactive amacrine and ganglion cells in the pre‐ and postnatal cat retina
Authors: Hutsler Jeffery J. , Chalupa Leo M. 
Published: January 2005

AbstractIn the adult cat, neuropeptide Y (NPY) immunoreactivity (IR) is found within a subgroup of gamma‐type ganglion cells and a large group of regularly arrayed amacrine cells. To examine the development of these two cell groups, we charted the appearance and maturation of neuropeptide Y immunoreactivity in the pre‐ and post‐natal cat retina. Neuropeptide Y immunoreactivity is first observed at the central retina within the ganglion cell layer on embryonci day 46, and immunoreactivity within amacrine cells of the inner plexiform layer is present by E50. The number of immunoreactive profiles reaches the adult level in the amacrine population first (around P7), while the ganglion cell population shows a protracted development, with new cells being added until the third postnatal week. NPY‐immunoreactive profiles in the ganglion cell layer were confirmed to be ganglion cells by retrograde labeling in both pre‐ and post‐natal animals. Thus, neuropeptide Y‐immunoreactive ganglion cells and amacrine cells attain their mature state with very different timecourses, although both cell groups initially follow a central to peripheral pattern of development. Interestingly, NPY expression within the ganglion cell population is temporally correlated with retinal synaptogenesis in the inner plexiform layer. As in the adult cat, NPY‐immunoreactive ganglion cells never show a regular distribution during development, while NPY‐IR amacrine cells are always distributed regularly even at the earliest ages. The prenatal presence of a regular distribution of NPY‐IR amacrine cells suggests that these cells may participate in establishing the ganglion cell mosaics that appear during postnatal development. © 1995 Wiley‐Liss, Inc.
Oculomotor control in calliphorid flies: Organization of descending neurons to neck motor neurons responding to visual stimuli
Authors: Gronenberg Wulfila , Milde Jürgen J. , Strausfeld Nicholas J. 
Published: January 2005

AbstractIn insects, head movements are mediated by neck muscles supplied by nerves originating in the brain and prothoracic ganglion. Extracellular recordings of the nerves demonstrate units that respond to visual stimulation of the compound eyes and to mechanosensory stimulation of the halteres. The number of neck muscles required for optokinetic eye movements in flies is not known, although in other taxa, eye movements can involve as few as three pairs of muscles. This study investigates which neck motor neurons are likely to be involved in head movements by examining the relationships between neck muscle motor neurons and the terminals visiting them from approximately 50 pairs of descending neurons. Many of these descending neurons have dendrites in neuropils that are associated with modalities other than vision, and recordings show that visual stimuli activate only a few neck motor neurons, such as the sclerite depressor neurons, which respond to local or wide‐field, directionally specific motion, as do a subset of descending neurons coupled to them. The results suggest that, like in the vertebrate eye or the retinas of jumping spiders, optokinetic head movements of flies require only a few muscles. In addition to the importance of visual inputs, a major supply to neck muscle centers by nonvisual descending neurons suggests a role for tactile, gustatory, and olfactory signals in controlling head position. © 1995 Wiley‐Liss, Inc.
Patterns of convergence and segregation in the medial nucleus accumbens of the rat: Relationships of prefrontal cortical, midline thalamic, and basal amygdaloid afferents
Authors: Wright Christopher I. , Groenewegen Henk J. 
Published: January 2005

AbstractIn the rat, fibers from the prelimbic cortex terminate in the medial nucleus accumbens. Anterior paraventricular thalamic and parvicellular basal amygdaloid fibers reach both the prelimbic cortex and the medial nucleus accumbens. All three afferent systems have an inhomogeneous distribution within the nucleus accumbens, and whether or not these projections actually reach the same areas is unknown. Our aim was to evaluate the relationships of the three afferents with respect to the shell, the core, and the cell clusters of the nucleus accumbens. Double anterograde tracing and single anterograde tracing combined with immunohistochemistry for calbindin (D28k) or Nissl stain was used. Following tracer injections in the prelimbic cortex and the anterior paraventricular thalamus, a complementary (i. e., nonoverlapping) pattern of was found in the shell. Thus, afferents from the prelimbic cortex are associated with cell clusters, whereas those from the anterior paraventricular thalamus avoid these cells but are affiliated with regions exhibiting weak homogeneous calbindin immunoreactivity. In the calbindin‐poor patches of the core, the situation is reversed as both sets of fibers overlap. In cases with injections in the prelimbic cortex and the parvicellular basal amygdala, a pattern of overlap was seen in the shell and core. Thus, the fibers in the shell were found together in association with cell clusters, whereas regions of weak homogeneous calbindin immunoreactivity were avoided. In the core, overlap was seen in the patch compartment. Finally, with parvicellular basal amygdala/paraventricular thalamus injections, a complementary fiber organization was present in the shell, but overlap was prominent in the patches of the core.The results demonstrate that the relationships of prelimbic cortical, paraventricular thalamic, and parvicellular basal amygdaloid afferents in the nucleus accumbens vary according to their compartmental (immunohistochemical and cellular) affiliation. Compartmentalization is therefore a possible anatomical substrate for condensation or segregation of neuronal signals passing through the nucleus accumbens. © 1995 Wiley‐Liss, Inc.
Morphology and connections of neurons in area 17 projecting to the extrastriate areas mt and 19DM and to the superior colliculus in the monkey Callithrix jacchus
Authors: Weisenhorn D. M. Vogt , Ilung R. B. , Spatz W. B. 
Published: January 2005

AbstractNeurons of area 17, the primary visual cortex, project to various anatomically and physiologically different extrastriate areas and subcortical regions. In the present investigation, we addressed the question of whether the efferent neurons in area 17 can contribute to functional diversity between these regions. We approached this question by analyzing the dendritic morphology of neurons in area 17 projecting to area MT, area 19DM, and the superior colliculus in the new world simian primate Callithrix jacchus, because dendritic morphology is an important factor in determinng physiological properties of nerve cells. Retrograde transport of fluorochromes injected into the target regions, and intracellular injections of Lucifer yellow in the prelabelled neurons, revealed the following. (1) Morphologically identical large pyramidal cells in layer VI of area 17 project to all three targets. Some of them possess axon collaterals to two or all three targets, suggesting that they provide common infcrmation to all three areas. (2) Pyramidal cells in layer IIIc projecting to area MT form a morphologically homogeneous population. (3) Three small to medium‐sized pyramidal cell types in layers IIIa‐c, spiny stellate cells in layer IIIc, and another large pyramidal cell type in layer VI project to area 19DM. (4) Pyramidal cells in the lower two‐thirds of layer V in area 17 project to the superior colliculus. In conclusion, we have shown that in Callithrix one efferent pathway may originate from several cell types. However, with the exception of the large cells in layer VI, efferent cells projecting to area MT, area 19DM, and the superior colliculus were morphologically distinct. This suggests that functional differences between brain regions could arise in part from morphological heterogeneity between and within the efferent cell populations. © Wiley‐Liss, Inc.