bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct projections from the dorsolateral pontine tegmentum to pudendal motoneurons innervating the external urethral sphincter muscle in the rat
Authors: Ding Yu‐Qiang , Takada Masahiko , Tokuno Hironobu , Mizuno Noboru
Published: January 2005

Direct projections from the dorsolateral pontine tegmentum to pudendal motoneurons innervating the external urethral sphincter and the external anal sphincter muscles were examined in the rat by the tract‐tracing methods utilizing retrograde transport of cholera toxin B subunit and anterograde transport of biotinylated dextran amine. The dorsolateral pontine tegmental region, corresponding to the micturition reflex center of Barrington, was confirmed to send bilaterally, with an ipsilateral dominance, projection fibers to the spinal parasympathetic nucleus (inferior intermediolateral nucleus). The micturition reflex center of Barrington, however, did not seem to send many projection fibers to the ventral horn of the lumbosacral cord segments, whereas the region immediately ventral to the micturition reflex center of Barrington was found to send bilaterally, with a contralateral dominance, projection fibers to the dorsolateral group of pudendal motoneurons in both the male and female rats. In the female rat, the dorsolateral group of pudendal motoneurons are comprised primarily of motoneurons that innervate the external urethral sphincter muscle. The dorsomedial group of pudendal motoneurons, which contain motoneurons that innervate the external anal sphincter and the bulbocavernosus muscles, did not seem to receive major projections from the dorsolateral pontine tegmental regions. It was also observed that the locus coeruleus sent some projection fibers bilaterally to the spinal parasympathetic nucleus but only a few to the ventral horn of the lumbosacral cord segments. Thus, the present results indicate that the dorsolateral group of pudendal motoneurons containing those innervating the external urethral sphincter muscle receive pontospinal projection fibers mainly from the dorsolateral pontine tegmental region immediately ventral to the micturition reflex center of Barrington. © 1995 Wiley‐Liss, Inc.
Differential innervation of protruder and retractor muscles of the tongue in rat
Authors: Dobbins Elizabeth G. , Feldman Jack L.
Published: January 2005

Protrusion 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

Retinoic 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

The 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

To 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

To 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

The 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

The 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

In 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

In 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

In 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

Neurons 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.
Metamorphosis of spinal‐projecting neurons in the brain of the sea lamprey during transformation of the larva to adult: Normal anatomy and response to axotomy
Authors: Swain Gary P. , Ayers Joseph , Selzer Michael E.
Published: January 2005

The spinal projecting system of the sea lamprey (Petromyzon marinus) has been used extensively in studies of axonal regeneration in both larvae and adults. However, little is known about the changes that are undergone by this system during metamorphosis. In order to determine the developmental changes in the size of the descending spinal projection and in the morphology of its neurons, larval, transforming, and adult lamprey brains were labeled by retrograde transport of horseradish peroxidase (HRP) injected into the spinal cord at 25% of body length. Examination of brain wholemount preparations revealed that the total number of labeled neurons doubled during metamorphosis. Most of this increase could be explained by elongation of reticulospinal axons from the rostralmost segments of the spinal cord to locations caudal to the injection site. There were no additions or deletions of either identified reticulospinal neurons or of reticulospinal nuclear groups between the larval and the adult stages. The proportions of Müller and Mauthner cells that were labeled reached a maximum of 93% during the early stages of metamorphosis. Axons of these neurons are known to project almost the entire length of the cord, even in larvae. Therefore, the efficiency of retrograde transport appears to be greater during metamorphosis than during larval or adult stages. While changes in efficiency of retrograde transport could account for some of the apparent increase in reticulospinal neuron numbers between larvae and animals undergoing metamorphosis, this could not contribute to the further increase in the apparent size of the reticulospinal system in the adult, since efficiency of retrograde labeling in these animals was lower than that at earlier stages. With retrograde labeling, a significant increase was seen in the profusion of dendritic arborization of some Müller and Mauthner cells during the early stages of metamorphosis. This correlated with an increase in the incidence of extreme axonal die‐back, as indicated by the presence of retraction bulbs within the brainstem. However, intracellular injection of Neurobiotin in untransected animals showed similar degrees of dendritic arborization at all examined stages of development. Therefore, the dendritic profusion did not reflect developmental changes in neuronal morphology but rather reflected an increased sensitivity to axotomy during metamorphosis. We conclude that, during the transformation of the lamprey from the large larval to the adult form, there is little change in either the size or the dendritic morphology of the identified giant reticulospinal neurons. With respect to the smaller reticulospinal neurons, the distance of projection of many of their axons increases during metamorphosis, but there is very little increase in the number of reticulospinal neurons. © 1995 Wiley‐Liss Inc.
Laminar patterns of expression of GABAA receptor subunit mRNAs in monkey sensory motor cortex
Authors: Huntsman M. M. , Woods T. M. , Jones E. G.
Published: January 2005

Radioactive complementary RNA probes, made from monkey‐specific cDNAs specific for the α1, α2, α4, α5, β1, β2, and γ2 and γ2 subunits of the γ‐aminobutyric acid A (GABAA) receptor were used for in situ hybridization histochemistry of the primary motor, somatosensory, and anterior parietal areas of thecerebral cortex in macaque monkeys.

mRNAs for the α1, β2, and α2, subunit polypeptides, which form receptors with the full range of classical properties, are expressed at much higher levels in all areas and show laminar and sublaminar‐specific concentrations. α2, α4, α5, and β1 subunit transcripts are expressed at much lower levels but also display individual, laminar‐specific concentrations; α5, expression, in particular, is highly expressed in layer IV in the somatosensory and parietal areas and in a layer IV‐like band in the motor cortex.

In layers in which expression of a particular transcript is high, all neurons may express the gene, but in layers in which expression is moderate, it is possible to detect differences in the degree of labeling of individual neurons for a particular mRNA, and some neurons may not express certain subunit transcripts in detectable amounts.

These findings indicate the variability in expression of different GABAA receptor subunits in the cerebral cortex. Laminar differences may indicate the assembly of functional receptors from different arrangements of available subunits in different classes of cells. © 1995 Wiley‐Liss Inc.
Ultrastructural basis for synaptic transmission between jaw muscle spindle afferents and trigeminothalamic neurons in the rostral trigeminal sensory nuclei of the rat
Authors: Luo Pifu , Wong Richard , Dessem Dean
Published: January 2005

Trigeminothalamic neurons were retrogradely labeled by injection of horseradish peroxidase into the ventroposteromedial nucleus of the thalamus in rats. Jaw‐muscle spindle afferent axons were then physiologically identified and intracellularly stained with biotinamide. The ultrastructure of labeled spindle afferent boutons was then studied in the caudolateral supratrigeminal region (Vsup) and dorsomedial trigeminal principal sensory nucleus (Vpdm). A total of 418 stained spindle afferent boutons were identified in Vsup and Vpdm; approximately 75% of these synapsed with dendrites, 10% synapsed with somata, and 15% synapsed with axons. Most jaw‐muscle spindle afferent boutons were postsynaptic to unlabeled P‐type boutons. Reciprocal synapses between spindle afferent boutons and unlabeled boutons were occasionally observed. A few dendrites in Vsup and Vpdm received synapses from multiple spindle afferent boutons. Conversely, some large (from 3 × 6 to 4 × 8 μm) and giant (from > 4 × 8 to 5 × 10 μm) spindle afferent boutons simultaneously contacted two to five dendrites and/or somata. Jaw‐muscle spindle afferent boutons also formed synapses with retrogradely labeled trigeminothalamic neurons in Vsup and Vpdm. Numerous unlabeled S‐and F‐type boutons converged onto the same trigeminothalamic dendrite or soma contacted by a spindle afferent bouton. A small number of synaptic triads consisting of an unlabeled P‐type bouton, a spindle afferent bouton, and either a dendrite or soina were also encountered. These data indicate that sensory feedback from the masticatory muscles is subject to presynaptic inhibition and integration prior to reaching the thalamus. This pathway is likely to be important in the relay of proprioceptive and kinesthetic information from the muscles of mastication to the thalamus. © 1995 Wiley‐Liss, Inc.
Morphological and functional effects of intranigrally administered GDNF in normal rhesus monkeys
Authors: Gash Don Marshall , Zhang Zhiming , Cass Wayne A. , Ovadia Aliza , Simmerman Linda , Martin David , Russell Deborah , Collins Frank , Hoffer Barry J. , Gerhardt Greg A.
Published: January 2005

Effects of a single injection of either 150 μg human recombinant glial cell line‐derived neurotrophic factor (rGDNF) or vehicle into the right substantia nigra were analyzed in 12 normal adult female rhesus monkeys. The studies included evaluating whole animal behavior, electrochemical recordings of striatal dopamine release, neurochemical determinations of basal ganglia and nigral monoamine levels, and immunohistochemical staining of the nigrostriatal dopamine system. The behavioral effects over the 3–week observation period following trophic factor administration were small, with blinded observers unable to distinguish between GDNF and vehicle‐treated animals. Quantitative measurements did show that five of six trophic factor recipients experienced some weight loss and four of the six GDNF recipients displayed small, but significant, increases in daytime activity levels. In vivo electrochemical recordings in the ipsilateral caudate and putamen 3 weeks after GDNF administration revealed increased potassium‐evoked release of dopamine in trophic factor recipients. In a second series of animals killed at the same time, dopamine levels in the substantia nigra and ventral tegmental area of GDNF recipients were significantly increased, with ipsilateral values more than 200% higher than contralateral and control levels. Levels of the dopamine metabolite HVA were significantly elevated in the substantia nigra, ventral tegmental area, and caudate nucleus ipsilateral to the trophic factor injection. There was a trend toward increased HVA levels in the ipsilateral putamen, nucleus accumbens, and globus pallidus in GDNF‐treated animals, but the ratios of HVA to dopamine were not significantly different between vehicle‐ and GDNF‐treated recipients. Although some tissue damage from the delivery of concentrated trophic factor was evident, dopamine neurons remained in and adjacent to the injection site. In the substantia nigra ipsilateral to GDNF administration, dopamine‐neuron perikaryal size was significantly increased, along with a significant increase in tyrosine hydroxylase‐positive axons and dendrites. We conclude that, in the adult rhesus monkey, a single intranigral GDNF injection induces a significant upregulation of mesencephalic dopamine neurons which lasts for weeks. © 1995 Wiley‐Liss, Inc.
Projections from visual areas of the cerebral cortex to pretectal nuclear complex, terminal accessory optic nuclei, and superior colliculus in macaque monkey
Authors: Lui Fausta , Gregory Kenneth M. , Blanks Robert H. I. , Giolli Roland A.
Published: January 2005

The purpose of this study was to analyze the projections from visually related areas of the cerebral cortex of rhesus monkey to subcortical nuclei involved in eye‐movement control; i. e., the pretectal nuclear complex, the terminal nuclei of the accessory optic system (AOS), and the superior colliculus (SC). The anterograde tracer 3H‐leucine was pressure injected bilaterally into the cortex of six monkeys (for a total of 12 cases) involving the primary visual cortex (area 17); the medial prestriate cortex (medial 18/19), dorsomedial area 19; the caudal portion of the cortex of the superior temporal sulcus, upper bank (cytoarchitectural area OAa) and lower bank (area PGa); the lower bank of the caudal lateral intraparietal sulcus (area POa); and the inferior parietal lobule (area 7).

The results revealed that the pretectal nucleus of the optic tract received inputs from medial prestriate cortex, dorsomedial part of area 19, OAa, and PGa. The posterior pretectal nucleus received sparse projections from area 7 and the cortex lining the intraparietal sulcus (dorsomedial part of area 19 and POa). The pretectal olivary nucleus was targeted by neurons in cortex of dorsomedial arec 19, and the anterior pretectal nucleus was targeted by neurons in both dorsomedial 19 and area 7.

The nuclei of the AOS (dorsal terminal; lateral terminal; and interstitial nuclei of the superior fasciculus, posterior and medial fibers) received projections exclusively from areas OAa and PGa. Furthermore, in one case with PGa injection, the medial terminal nucleus, dorsal portion, was also labeled.

The visual cortical areas studied projected differentially upon the SC laminae. The primary visual area 17 projected only to the superficial laminae, i. e., stratum zonale (SZ), stratum griseum superficiale (SGS), and stratum opticum (SO). On the other hand, the medial portion of the prestriate cortex and caudal OAa and PGa targeted the superficial and intermediate laminae, i. e., SZ, SGS, SO, stratum griseum intermediale (SGI), whereas caudal area POa projected primarily to the intermediate layer SGI. Rostral area 7 (mainly 7b) neurons terminated in the stratum album intermediale (SAI); no SC terminals were found in a case in which caudal area 7 (mainly 7a) was injected. © 1995 Wiley‐Liss, Inc.
Immunocytochemical localization of Diploptera punctata allatostatin‐like peptide in Drosophila melanogaster
Authors: Yoon Jae G. , Stay Barbara
Published: January 2005

Allatostatins isolated from the cockroach Diploptera punctata are a family of neuropeptides that inhibit juvenile hormone synthesis in cockroaches and related insects but not in flies. In cockroaches, these widely distributed peptides have been shown to have other functions. This report provides evidence for the presence of allatostatin‐like peptides in Drosophila melanogaster by demonstration of allatostatic activity of extracts of central nervous system from larvae and adults on corpora allata of Diploptera and by immunocytochemical localization of peptides in Drosophila with monoclonal antibody against Diploptera allatostatin I. Extract of adult central nervous system showed four times more allatostatic activity than that of the larva or twice the activity per unit volume of central nervous system. This is reflected in an increase in number and arborization of immunoreactive neurons in the adult. The immunoreactive neurons in the central nervous system appear to be interneurons, with the exception of motoneurons in the last abdominal neuromere that project to muscles of the hindgut, a pair of peripheral cells in each of two thoracic segments in the larva and on nerves to wings and halteres in the adult, and endocrine cells of the midgut epithelium. Nerves to the corpus allatum were not immunoreactive. The presence of Diploptera allatostatin‐like peptides in interneurons and motoneurons, in the neurohemal networks, and in endocrine cells of the midgut and their absence in nerves to the corpus allatum in Drosophila suggests that these peptides may function as neuromodulators, myomodulators, and neurohormones and not as regulators of the corpus allatum. © 1995 Wiley‐Liss, Inc.
Intracerebroventricular kainic acid administration in adult rat alters hippocampal calbindin and non‐phosphorylated neurofilament expression
Authors: Shetty Ashok K. , Turner Dennis A.
Published: January 2005

Calbindin and non‐phosphorylated neurofilament proteins were assessed in hippocampus following a unilateral intracerebroventricular kainic acid injection at 4, 26, and 60 days post‐lesion, using immunocytochemical expression. The density of calbindin‐positive non‐ pyramidal neurons throughout the hippocarnpus showed no significant alteration at 4 days post‐lesion, a significant decrease at 26 days post‐lesion, and a partial recovery at 60 days post‐lesion. In addition, calbindin immunoreactivity was dramatically reduced at 26 days post‐lesion in the CA1 pyramidal and dentate granule cell layers and the mossy fibers, bilaterally. Although not significant statistically, most of these reductions showed signs of reversal at 60 days post‐lesion except the CA1 pyramidal cell layer where the dramatic reductions persisted. Neurofilaments were also altered throughout the post‐lesion period, particularly in abnormal expression of non‐phosphorylated neurofilament proteins in mossy fibers. The apparent return of calbindin immunoreactivity in non‐pyramidal neurons by 60 days post‐lesion suggests that recovery from the lesion may involve remaining neuronal elements which either become reactivated with time or have the capability to express normal levels of calbindin with re‐innervation. On the other hand, prolonged calbindin reductions in superficial CA1 pyramidal cells suggest sustained down‐regulation of calbindin expression owing to persistent reductions in the activity of these neurons. The temporal correlation of the expression of non‐phosphorylated neurofilamenta in mossy fibers with their sprouting response following target loss suggests a potential role for non‐phosphorylated neurofilaments in neuronal plasticity involving axonal sprouting. Alternatively, it may also suggest that injury‐ induced neurofilament modifications are either conducive or permissive for axonal sprouting. © 1995 Wiley‐Liss, Inc.
A note on the significance of the small volume of the nerve cell bodies in the cerebral cortex in man
Authors: Donaldson Henry H.
Published: January 2005

The weight of all the nerve cell bodies in the human encephalon is less than 27 grams.

When comparison is made of human encephala grouped according to race, sex, mental power, stature and age, the differences in weight, within each group, are always more than twice that of the nerve cell bodies, and hence these differences depend mainly on variations in the medullary substance

Small variations in the mass of the nerve cell bodies (though physiologically highly important) escape detection by the method of weighing, or may be masked by the greater growth of the medullary substance.
Saccharin‐taste discrimination by two‐lever choice: A rat bioassay for sweeteners
Authors: Shearman Gary T. , Cafaro Michael P. , Lal Harbans , Howard James L.
Published: January 2005

Male hooded rats were trained to discriminate the taste of a saccharin solution from that of water by responding with a lever on one side of a food cup following 20 licks (500 μl) of a 0.002 M saccharin solution and responding with a lever on the alternate side following 20 licks (500 μl) of water for food reinforcement. All of the rats learned this discrimination reliably. The gustatory stimulus produced by saccharin was concentration‐dependent. Sucrose (0.01–0.1 M) and dextrose (0.1–0.5 M) produced a concentration‐dependent generalization to the saccharin taste. Solutions of sodium chloride (0.15 M), citric acid (0.01 M), caffeine citrate (0.01 M), and quinine hydrochloride (0.00001–0.01 M) did not produce saccharin‐like taste. Generalization of sweet compounds and lack of generalization of salty, sour, and bitter compounds to the saccharin taste suggest that discrimination of the nonnutritive sweetener, saccharin, by the rat may possibly be used as a bioassay to detect and quantitate the sweetening property of new compounds.
Correlation of behavioral and neurochemical effects of d‐ and l‐amphetamines
Authors: Aulakh C. S. , Bhattacharyya A. K. , Pradhan S. N.
Published: January 2005

In an attempt to correlate the behavioral and neurochemical effects of d‐ and l‐amphetamines, the time courses of the effects of the two isomers (1 mg/kg; base, i.p.) were studied on spontaneous motor activity (SMA) and stereotyped behavior (ST) as well as on the concentrations of norepinephrine (NE), dopamine (DA), and serotonin (5‐HT) in discrete brain areas, such as the caudate nucleus (CN), pons‐medulla (PM), and diencephalonmidbrain (DM) in rats. In addition, the dose‐response relationship for d‐isomer (0.5–2 mg/kg, i.p.) and l‐isomer (1–4 mg/kg, i.p.) was also studied on SMA and ST. SMA increased with the dose up to 1.5 mg/kg for d‐isomer and up to 3 mg/kg for l‐isomer and then decreased, whereas ST increased with the dose for both the isomers. At 1 mg/kg dose, SMA reached its peak during the fourth postdrug 20–minute period for both d‐ and l‐isomers, whereas ST reached its peak during third to fifth 20‐minute periods for d‐isomer and during the third period for the l‐isomer. The d‐isomer significantly increased the DA levels in the CN and DM at 30 minutes postdrug, which reached their maximum at 60 minutes, whereas NE levels in the PM had no significant change at 30 minutes, but were significantly reduced in the DM at 30 minutes and in both PM and DM at 60 minutes postdrug; 5‐HT levels in the PM and DM showed no significant change. Compared to d‐amphetamine, the l‐isomer at 30 and 60 minutes postdrug caused more or less similar changes in the NE levels in the DM and PM, whereas it produced less increase in the DA levels in the CN and DM and significant decrease in 5‐HT levels in the DM and PM. It appears that the difference in the behavioral effects induced by the two isomers of amphetamine may be due to the difference in their effects on dopaminergic and serotonergic systems.
Glucocorticoid regulation of lung beta‐adrenergic receptors
Authors: Scarpace Philip J. , Abrass Itamar B.
Published: January 2005

To test the hypothesis that glucocorticoids modulate lung beta‐adrenergic receptors as a mechanism for their therapeutic effect in asthma, we investigated the effects of adrenalectomy and glucocorticoid administration on rat lung beta‐adrenergic receptors. The data demonstrate that, compared to untreated animals, adrenalectomized Sprague‐Dawley rats treated with cortisol (80 mg/kg) for 5 days and nonoperated rats treated with methylprednisolone (100 mg/kg) for 5 days have a 30% increase in lung beta‐adrenergic receptors, as measured by [3H]‐dihydroalprenolol binding. These data support the hypothesis that pharmacological doses of glucocorticoids modulate lung beta‐adrenergic receptors upwards. This mechanism may account, at least in part, for the therapeutic effect of these drugs in asthma.
Effect of cyproterone acetate and conjugated estrogens on the human insulin receptor
Authors: De Pirro Roberto , Forte Fiorella , Liberti Marcello , Gallucci Michele , Monaco Fabrizio , Lauro Renato
Published: January 2005

It has recently been reported that prednisone increases whereas dexamethasone and cortisone decrease insulin binding to monocytes, thus suggesting that different steroids may exert opposite effects on the insulin receptor, depending on their chemical structure. In order to gain further insight into the modulations of the insulin receptor by other steroids, the effect in male patients of short‐ and long‐term oral treatment with cyproterone acetate (100–150 mg/day) or conjugated estrogens (20 mg/day) was evaluated. Cyproterone acetate did not produce any statistical, evident change in insulin binding to monocytes after either short‐term (5 days) or long‐term (1 year) treatment. Short‐term (5 days) administration of conjugated estrogens did not affect insulin binding; however, long‐term (1 year) treatment produced a highly significant decrease in insulin binding due mainly to changes in receptor concentration. Thus, cyproterone acetate does not affect the insulin receptor, whereas conjugated estrogens reduce insulin receptors after long‐term treatment, as with dexamethasone and cortisone.

Estrogens probably play a role in the insulin binding impairment which occurs during the luteal phase of the menstrual cycle as well as in users of the “pill”.