bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of GABA‐immunoreactive nerve fibers and cells in the cervical and thoracic paravertebral sympathetic trunk of adult rat: Evidence for an ascending feed‐forward inhibition system
Authors: Wolff J. R. , Kása P. , Dobó E. , Römgens H. J. , Párducz Á. , Joó F. , Wolff A. 
Published: January 2005

AbstractNeurochemical and immunohistochemical evidence suggests that the superior cervical ganglion (SCG) contains all components of a gamma‐aminobutyric acid (GABA)ergic transmission system, which includes GABAergic axons of unknown origin. The number of nerve fibers with and without GABA‐like immunoreactivity was determined in interganglionic connectives at all cervical and thoracic levels of the paravertebral sympathetic trunk. In addition, the distribution of GABA‐immunoreactive (IR) neurons was established within the ganglion chain and compared with the relative frequency of principal neurons richly innervated by GABA‐IR axon terminals.The following results were obtained: (1) the total number of nerve fibers in cross sections did not significantly vary between the cervical levels, but it increased steadily from upper to lower thoracic segments; (2) in contrast, the number of GABA‐IR fibers decreased from the cervical sympathetic trunk below the SCG (∼300 fibers) down to the seventh to tenth thoracic ganglion, below which no such fiber was seen; (3) GABA‐IR nerve fibers originate from a subclass of GABA‐IR cells; these are small, bipolar neurons with predominantly ascending, unmyelinated axon‐like processes; (4) the number of principal neurons richly innervated by GABA‐IR nerve fibers decreased from the SCG to the upper thoracic ganglia, and was very small below; and (5) apart from basket‐like innervation, GABA‐IR axons also formed diffuse networks around GABA‐negative principal neurons predominantly in cervical and upper thoracic ganglia. These data suggest that the GABAergic innervation of paravertebral sympathetic ganglia is more complex than previously suspected. What appears as preganglionic afferents from several spinal segments (C8‐Th7) innervate GABAergic neurons in the sympathetic trunk which have ascending axons and focus their inhibitory effects on the cervical sympathetic ganglia, predominantly the SCG. These data suggest that GABAergic small interganglionic neurons form a feed‐forward inhibition system, which may be driven by multisegmental spinal input in the paravertebral sympathetic ganglion chain. © 1993 Wiley‐Liss, Inc.
Restoration of substance P and calcitonin gene‐related peptide in dorsal root ganglia and dorsal horn after neonatal sciatic nerve lesion
Authors: Nothias Fatiha , Tessler Alan , Murray Marion 
Published: January 2005

AbstractDorsal root ganglion (DRG) neurons decrease their substance P (SP) synthesis after peripheral nerve lesions. Levels in the dorsal horn also decline but return to normal if regeneration is successful. In adults, when regeneration is prevented, recovery of SP in the dorsal horn is slow and incomplete, whereas in newborns, recovery is rapid and complete even though retrograde cell death of DRG neurons is greater than in adults. We have examined the mechanisms that might account for the rapid and complete recovery of SP and calcitonin‐gene related peptide (CGRP) in the dorsal horn after peripheral nerve injury in newborns. Peptides were compared in the L4 and L5 DRG and spinal cord segments of normal rats and in rats surviving 6 days to 4 months after sciatic nerve section/ligation within 24 hours of birth.Sciatic nerve section/ligation produced 50% neuron death in L4 and L5 DRGs, but immunocytochemical methods showed that both SP‐immunoreactivity (‐IR) and CGRP‐IR recovered completely in dorsal horn. Radioimmunoassay confirmed that recovery of SP was not an artefact due to shrinkage. β‐Preprotachykinin (PPT)‐mRNA hybridization and SP‐IR were observed mostly in small neurons; α‐CGRP‐mRNA‐hybridized and CGRP‐IR neurons were more heterogeneous. The percentage of DRG neurons that contained SP (∼ 25%) or CGRP (∼ 50%) was the same in normal newborn and adult rats. Neither selective cell survival nor change in neuron phenotype was likely to contribute to the recovery seen in the dorsal horn, and DRG neurons ipsilateral to the lesion exhibited the same level of hybridized β‐PPT‐mRNA and α‐CGRP‐mRNA as intact DRG neurons. Because neither the constitutive level of expression of the genes nor peptide levels increased above those observed in intact DRG neurons, these mechanisms were also not responsible. Axotomized DRG neurons, however, contributed to recovery. Recovery was also due to sprouting by neurons in intact DRGs rostral and caudal to L4 and L5. © 1993 Wiley‐Liss, Inc.
Anatomy of the mushroom bodies in the honey bee brain: The neuronal connections of the alpha‐lobe
Authors: Rybak Jürgen , Menzel R. 
Published: January 2005

AbstractNeural connections between the mushroom body (MB) and other protocerebral areas of the honeybee's brain were studied with the help of cobalt chloride and Golgi staining methods. Focal injections of cobalt ions into the α‐lobe neuropil of the MB reveal seven clusters of somata located in the protocerebrum and deutocerebrum of each brain hemisphere. These neurons connect the mushroom body neuropil with protocerebral areas and number approximately 400. They contact the layered organization of the α‐lobe at different locations. Some project not only into the α‐lobe, but also into the β‐lobe and pedunculus neuropils. Fifteen cell types which form intraprotocerebral circuits are morphologically described. They can be divided into three categories: (1) unilateral neurons, with projection fields restricted to the ipsilateral protocerebrum; these neurons connect the α‐lobe with areas in the protocerebral lobe and ramify with densely layered arborisations arranged perpendicularly to the longitudinal axis of the α‐lobe; (2) recurrent neurons, which interconnect subcompartments of the MB, forming loops at different leveles of the neuropil; their arborisations are mainly restricted to the α‐lobe, β‐lobe, pedunculus, and calyces of the ipsilateral MB; they also ramify sparsely around the neuropil of the α‐lobe; and (3) bilateral neurons, which either interconnect both α‐lobes or connect the ipsilateral α‐lobe and protocerebral lobe with the dorsolateral protocerebral lobe of the conntralateral hemisphere. The connections of different compartments of the MB with other parts of the protocerebrum as revealed in this study are discussed in the context of hypotheses about the functional role of MBs in the honeybee brain. © 1993 Wiley‐Liss, Inc.
Origin of serotoninergic afferents to the hypoglossal nucleus in the rat
Authors: Manaker Scott , Tischler Laura J. 
Published: January 2005

AbstractThe hypoglossal nucleus contains serotonin and several different serotonin receptors, and serotonin is present in fibers and terminals contacting hypoglossal motoneurons. Serotonin alters the excitability of hypoglossal motoneurons, and may influence hypoglossal motoneuron activity in a variety of physiological processes. Since the hypoglossal nucleus contains no serotoninergic somata, the present study sought to identify the sources of serotoninergic afferents to the hypoglossal nucleus. Fluorogold was injected into the hypoglossal nucleus and serotoninergic immunofluorescence was utilized in a dual‐fluorescence technique to identify the sources of serotoninergic afferents to the hypoglossal nucleus. The results demonstrate that most serotoninergic afferents to the hypoglossal nucleus originate from the nuclei raphe pallidus and obscrus, while fewer originate from the nucleus raphe magnus and the parapyramidal region. Other regions of the medial tegmental field and the pons that contain both serotoninergic neurons and neuronal afferents to the hypoglossal nucleus contain no double‐labeled neurons. © 1993 Wiley‐Liss, Inc.
The dorsomedial visual area of owl monkeys: Connections, myeloarchitecture, and homologies in other primates
Authors: Krubitzer Leah A. , Kaas Jon H. 
Published: January 2005

AbstractCortical connections of the dorsomedial visual area (DM) of owl monkeys were revealed with injections of the bidirectional tracer, wheatgerm agglutinin conjugated with horseradish peroxidase (WGA‐HRP), or the retrograde fluorescent tracer, diamidino yellow. Microelectrode recordings in two cases identified DM as a systematic representation of the visual hemifield in a densely myelinated rectangle of cortex just rostral to the dorsomedial portion of the second visual area (V–II, or area 18). Cortex was flattened and cut parallel to the surface in all cases so that the myeloarchitectonic borders of DM and other areas such as the primary visual area (V‐I or area 17), V‐II or area 18, and the middle temporal visual area (MT) could be readily determined, and the surface view patterns of connections could be directly appreciated. The ipsilateral pattern of connections of DM were dense and visuotopically congruent with area 17, area 18, and MT, and moderate to dense connections were with the medial visual area (M), the rostral division of the dorsolateral visual area, the dorsointermediate area, the ventral posterior area, the caudal division of inferotemporal cortex (ITc), the ventral posterior parietal area, and visuomotor cortex of the frontal lobe. The connections of DM were concentrated in the cytochrome oxidase (CO)‐dense blobs of area 17, the CO‐dense bands of area 18, and the CO‐dense regions of MT. Callosal connections of DM were with matched locations in DM in the opposite hemisphere, and with VPP.The ipsilateral connections of DM with area 17 were confirmed by injecting WGA‐HRP into area 17 in one owl monkey. In addition to labelled cells and terminals in area 18 and MT, bidirectionally transported tracer was also apparent in DM. Evidence for the existence of DM in other primates was obtained by injecting area 17 and examining the areal patterns of connections and myeloarchitecture in three species of Old World monkeys, two additional species of New World monkeys, and prosimian galagos. In all of these primates, one of three major targets of area 17 was a densely myelinated zone of cortex just rostral to dorsomedial area 18, in the location of DM in owl monkeys. Thus, it seems likely that DM is a visual area common to all primates. © 1993 Wiley‐Liss, Inc.
Central retinal area is not the site where ganglion cells are generated first
Authors: Rager Ute , Rager Günter , Frei Bernard 
Published: January 2005

AbstractThe development of retinal ganglion cells (RGC) was studied in the chick from stage 18 to adulthood. Our main objectives were to identify the retinal site where the first RGCs differentiate, to locate this site relative to the optically defined central retinal area, and to map the spatial arrangement of the RGC field at different stages in development. The eyes of the experimental animals were fixed and serially sectioned. The borders of RGC fields were determined from the presence of either ganglion cell perikarya or ganglion cell axons. In seven cases between stages 21 and 26, the borders of the RGC fields were confirmed electron microscopically. The serial sections together with the RGC fields were then reconstructed in three dimensions. The reconstructed retinae were projected onto a plane by using the radially equidistant polar azimuthal projection.First, RGCs appear dorsal to the apex of the optic fissure. Ganglion cell development then initially spreads out symmetrically with respect to the optic fissure. However, from stage 29 on, the nasal half of the retina expands much more than the temporal half. This asymmetrical growth entails that the optic fissure is eventually located in the temporal half of the retina in the mature animal.The RGC fields of the embryonic stages were superimposed on the retina of a visually active animal according to their real size and position. It turned out that the central retinal area was at least 2 mm away from the site where the first RGCs were generated. It is not before stage 28 that the prospective central retinal area is included into the expanding ganglion cell field. The fact that RGCs at the central retinal area are generated 2.5 days later than first RGCs near the apex of the optic fissure has important implications for the formation of the retinotectal projection. © 1993 Wiley‐Liss, Inc.
Immunohistochemical localization of a ligand‐binding and a structural subunit of nicotinic acetylcholine receptors in the central nervous system of Drosophila melanogaster
Authors: Schuster Renate , Phannavong Bounpheng , Schröder Christiane , Gundelfinger Eckart D. 
Published: January 2005

AbstractThe distribution of two subunits of nicotinic acetylcholine receptors in the developing and the differentiated central nervous system of Drosophila melanogaster was studied. With subunit‐specific antibodies raised against the ligand‐binding α‐like subunit ALS and the putative non‐ligand‐binding subunit ARD, we find both ALS‐like and ARD‐like immunoreactivity widely distributed in most neuropiles of the optic lobes, the protocerebrum, the deutocerebrum and the thoracic ganglion of the adult fly. With a single exception, namely in the lamina of the visual system, the antigens recognized by the two types of antibodies are colocalized. This observation is consistent with previous immunoprecipitation data indicating that the ALS and ARD proteins are integral components of the same hetero‐oligomeric receptor that binds the nicotinic antagonist α‐bungarotoxin with high affinity. During embryonic development ARD‐like immunoreactivity is first detectable in ≈︁ 10 hour old embryos. Both subunits are consistently detected in the central nervous system ofthe late embryo, the three larval stages, and all prepupal and pupal stages. During metamorphosis the optic stalk is transiently immunoreactive with anti‐ARD, but not with anti‐ALS antiserum. Although in larvae and adults, immunoreactivity with both types of antibodies is most abundant in synaptic regions, in embryos and pupae strong staining of cortical cell body layers is observed, in particular with anti‐ARD antisera. As these developmental periods coincide with strong accumulation of ARD transcripts, the cell body staining may reflect newly synthesized and assembled receptors, while the functional ARD‐ and ALS‐containing receptor may be destined for synapses. © 1993 Wiley‐Liss, Inc.
Synapses between slowly adapting lung stretch receptor afferents and inspiratory beta‐neurons in the nucleus of the solitary tract of cats: A light and electron microscopic analysis
Authors: Anders Klaus , Ohndorf Wolfgang , Dermietzel Rolf , Richter Diethelm W. 
Published: January 2005

AbstractPrevious neuroanatomic and physiologic studies indicated that afferent fibres from slowly adapting pulmonary stretch receptors (SAR) project to the nuclei of the solitary tract and terminate on inspiratory beta‐neurons. In the present study we combined electrophysiologic and morphologic approaches to verify the presumed monosynaptic connections between SARs and beta‐neurons.Single identified beta‐neurons and single identified SAR afferent fibres were labelled intrasomally and intraaxonally, respectively, with horseradish peroxidase (HRP) in the same anesthetized cats. Under the light microscope, we analyzed the morphology of beta‐neurons and their dendritic fields and of the terminal projection pattern of fibres from SARs and identified potential synaptic connections between boutons of SAR afferent fibres and the soma and dendrites of beta‐neurons. The identified tissue was then processed further for electron microscopic analysis.On average, beta‐neurons had 6 primary dendrites that bifurcated 3–8 times. The dendritic trees extended 1.5 mm both rostrocaudally in the ventrolateral nucleus of the solitary tract and medially into the intermediate subnucleus. Axons of beta‐neurons curved toward the midline and no collateral branches were evident over its stained length (2.5–3.4 mm).Axodendritic synaptic contacts between SAR fibres and beta‐neurons were identified electron microscopically in four of six tissue samples chosen by light microscopy. In addition, we located 2 axodendritic and 2 axosomatic synaptic contacts that were not observed under light microscopic screening. The boutons of SAR fibres contained clear, round vesicles and formed asymmetrical synapses with beta‐neurons. Multiple synaptic connections were found between collaterals of a single SAR and single beta‐neurons, indicating a dense terminal projection of single SAR afferent fibres onto beta‐neurons. These morphologic data prove monosynaptic connections between electrophysiologically identified SAR afferent fibres and beta‐neurons. © 1993 Wiley‐Liss, Inc.
Correlations between the receptive field properties and morphology of neurons in the deep layers of the hamster's superior colliculus
Authors: Mooney Richard D. , Nikoletseas Michael M. , King Tod D. , Savage Steven V. , Huang Xiaoguang 
Published: January 2005

AbstractExtracellular and intracellular recording, receptive field mapping, and intracellular HRP injection techniques were used to define the morphological classes of cells in the deep laminae of the hamster's superior colliculus and to determine whether there are any correlations between the structural and functional characteristics of these neurons. A total of 110 neurons were characterized and reconstructed. Of these, 23.6% (N = 26) were visual, 60% (N = 66) were somatosensory, 0.9% (N = 1) were bimodal (visual‐somatosensory), and 15.4% (N = 17) were unresponsive. Of the somatosensory neurons, 72.7% (N = 48) were low threshold, 4.5% (N = 3) had a wide dynamic range, 9.1% (N = 6) responded only to noxious stimulation, and 13.6% (N = 9) had complex somatosensory receptive fields.Deep layer cells were divided into eight morphological classes. These classes were multipolar cells (26.4%, N = 29), bipolar cells (9.1%, N = 10), widefield vertical cells (7.3%, N = 8), horizontal cells (13.6%, N = 15), stellate cells (10.9%, N = 12), ventrally directed cells (5.5%, N = 6), sparse radial cells (17.3%, N = 19), and small sparse radial cells (6.4%, N = 7). Four cells (3.6%) did not fit into this classification scheme. Univariate and multivariate analyses of variance of properties such as soma area, number of branch points, total dendritic length, and volume and orientation of dendritic arbor indicated that these classes were significantly different. However, X2 analysis and multivariate analysis of variance indicated no significant relationships between morphological class and either laminar location or receptive field type. There was a significant positive relationship between the possession of dendrites that extended into the superficial laminae and visual responsivity. © 1993 Wiley‐Liss, Inc.
Expiratory neurons of the bötzinger complex in the rat: A morphological study following intracellular labeling with biocytin
Authors: Bryant Thomas H. , Yoshida Shigetaka , de Castro Denis , Lipski J. 
Published: January 2005

AbstractThe term “Bötzinger Complex” (BOT) refers to a distinct group of neurons, located near the rostral portion of the nucleus ambiguus, which are known to play an important role in the control of respiratory movements. Previous studies conducted in cats have demonstrated that most of these neurons are active during expiration, exerting a monosynaptic inhibitory action on several subpopulations of inspiratory neurons in the medulla and spinal cord. The aim of this study was to examine morphological properties and possible synaptic targets of BOT neurons in the rat. Forty‐one expiratory neurons were labeled intracellularly with biocytin; 12 were interneurons (BOT neurons) and 29 were motoneurons. The latter could not be antidromically activated following stimulation of the superior laryngeal or vagal nerves. BOT neurons showed extensive axonal arborisations in the ipsilateral medulla, with some projections to the contralateral side. Bouton‐like axon varicosities mainly clustered in two areas: near the parent cell bodies, and in the area corresponding to the rostral part of the ventral respiratory group (VRG). In five pairs of labeled neurons, each consisting of one BOT neuron and one inspiratory neuron in the rostral VRG, no appositions were identified at the light microscopic level between axons of BOT neurons and dendrites or cell bodies of inspiratory neurons. These results demonstrate that some features of BOT expiratory neurons in the rat are similar to those previously described in cats. The differences include their more ventral location in relation to the compact formation of nucleus ambiguus (retrofacial nucleus), and the relative paucity in the rat of neurons displaying an augmenting pattern of activity and of neurons with spinally projecting axons. In addition, we were unable to find morphological evidence for contacts between labeled BOT neurons and ipsilateral inspiratory neurons near the obex level, a finding not consistent with previous electrophysiological studies in the cat in which such synaptic connections have been identified. © 1993 Wiley‐Liss, Inc.
Nerve growth factor receptor (p75)‐immunoreactivity in the normal adult feline trigeminal system and following retrogasserian rhizotomy
Authors: Henry Michael A. , Westrum Lesnick E. , Bothwell Mark , Johnson Lonnie R. 
Published: January 2005

AbstractThe 75 kDa protein nerve growth factor receptor [NGFr(p75)] is a neurotrophin receptor that is able to bind different members of the neurotrophin family of molecules implicated in affecting neruronal survival. Here we describe the light microscopic distribution of NGFr(p75)‐immunoreactivity (IR) within the feline trigeminal brainstem sensory nuclear complex and trigeminal ganglion of normal adult subjects and in subjects 10 and 30 days following retrogasserian rhizotomy. Within the trigeminal ganglion of normal subjects, numerous fibers and most of the neuronal cell bodies showed NGFr(p75)‐IR that varied in intensity, while cells and fibers with NGFr(p75)‐IR were less numerous within the mesencephalic trigeminal nucleus. Within the main sensory and spinal trigeminal nuclei, NGFr(p75)‐IR formed a reproducible pattern that varied between the different subnuclei. The NGFr(p75)‐IR consisted both of dense pockets and a low level NGFr(p75)‐IR that was selective to the trigeminal neuropil. Following rhizotomy, most of the NGFr(p75)‐IR was lost from the main sensory and spinal trigeminal nuclei, except in regions where the upper cervical roots and cranial nerves VII, IX, and X project. In contrast, examination of the central root that was still attached to the trigeminal ganglion showed increased NGFr(p75)‐IR in fibers and supporting cells, as did the motor root within the peripheral mandibular division. These results indicate that the majority of the NGFr(p75)‐IR within the main sensory and spinal trigeminal nuclei originates from primary trigeminal afferents and that retrogasserian rhizotomy leads to an up‐regulation of NGFr(p75)‐IR in the part of the central root that is contiguous with the ganglion. © 1993 Wiley‐Liss, Inc.