bluuebunny/crossref_metadata_2025_split huggingface dataset:
Projections of individual purkinje cells of identified zones in the flocculus to the vestibular and cerebellar nuclei in the rabbit
Authors: De Zeeuw C. I. , Wylie D. R. , Digiorgi P. L. , Simpson J. I. 
Published: January 2005

AbstractThe rabbit flocculus can be divided into five zones (zones 1, 2, 3, 4, and C2) with the use of acetylcholinesterase histochemistry. The projections of individual Purkinje cells in these zones to the vestibular and cerebellar nuclei were studied by using biocytin as an anterograde tracer. The zones were physiologically identified in terms of the Purkinje cell complex spike modulation occurring in response to optokinetic stimulation. In zones 1 and 3 neurons respond best to rotation about a horizontal axis that is close to perpendicular to the ipsilateral anterior semicircular canal, whereas in zones 2 and 4 neurons respond best to rotation about the vertical axis. Complex spike activity in zone C2 is unresponsive to optokinetic stimulation.Collectively, Purkinje cells of zone 1 projected to the ventral dentate nucleus, dorsal group y, and superior vestibular nucleus; Purkinje cells of zones 2 and 4 projected to the magnocellular and parvicellular parts of the medial vestibular nucleus; Purkinje cells of zone 3 projected to dorsal group y, ventral group y, and the superior vestibular nucleus; and Purkinje cells of zone C2 projected to the interposed posterior nucleus and dorsal group y. Some of the labeled Purkinje cell axons branched and innervated two nuclei. Branching axons from zone 1 either innervated both the ventral dentate nucleus and the superior vestibular nucleus or both dorsal group y and the superior vestibular nucleus. Branching axons from zones 2 and 4 innervated both the magnocellular and the parvicellular parts of the medial vestibular necleus. Branching axons from zone 3 innervated both dorsal group y and the superior vestibular nucleus, or both ventral group y and the superior vestibular nucleus. Branching axons from zone C2 innervated both the interposed posterior nucleus and dorsal group y.Some of the target nuclei of the floccular Purkinje cell axons (e. g., dorsal group y and interposed posterior nucleus) project to the part of the inferior olive that, in turn, projects to the corresponding floccular zone, thus completing a closed pathway consisting of the inferior olive, the cerebellar cortex, and the cerebellar and vestibular nuclei. Other target nuclei (e. g., superior vestibular nucleus and medial vestibular nucleus) do not project back to the olivary subnuclei that innervate the flocculus and are part of an open olivofloccular pathway. An individual Purkinje cell thus can innervate a nucleus in the closed pathway as well as a nucleus in the open pathway. To summarize, the present study illustrates that floccular Purkinje cells located in discrete zones are part of different pathways involved in the regulation of specific components of compensatory eye movements. © 1994 Wiley‐Liss, Inc.
Thalamic connections of the primary motor cortex (M1) of owl monkeys
Authors: Stepniewska Iwona , Preuss Todd M. , Kaas Jon H. 
Published: January 2005

AbstractTo determine the relative contributions of transthalamic cerebellar and pallidal projections to the primary motor cortex (M1) of owl monkeys, we examined the thalamic labeling resulting from injections of fluorescent tracers and wheatgerm agglutinin/horseradish peroxidase conjugate (WGA‐HRP) into regions of M1 identified by intracortical microstimulation. Injections were placed in the major somatotopic divisions of M1 (the hindlimb, trunk, forelimb, and face representations) and in the caudal and rostral M1 subareas. In most cases, we injected several differentiable tracers into different parts of M1. Our results indicate that the strongest connections of M1 are with subdivisions of the ventral lateral thalamus (VL); other connections are mainly with intralaminar nuclei (the central lateral, paracentral, and center median nuclei) and the reticular nucleus. Most projections are reciprocal and topographically organized. M1 is strongly connected with the principal (VLp), medial (VLx), and anterior (VLa) subdivisions of the VL complex but has at most weak connections with the dorsal division (VLd). Each of the major somatotopic divisions of M1 is connected with an anteroposteriorly elongated territory within the VL complex. The connections are somatotopically organized such that the M1 hindlimb representation is connected with a band of cells in the lateral and anterior portions of the VL complex (spanning VLa and VLp), whereas the trunk, forelimb, and face representations are connected with successively more medially and posteriorly situated cell bands (spanning VLa, VLp, and VLx). There is some degree of overlap between the somatotopic territories within VL, although the absence of double‐labeled cells in cases with injections of adjacent somatotopic divisions of M1 suggests that individual thalamic neurons project to single somatotopic regions.In addition to somatotopic differences, the connections of the caudal and rostral subdivisions of M1 differ to some extent. Caudal M1 is connected most strongly with VLp, a target of cerebellar projections, but it is also connected with VLa, which receives pallidal inputs. In complementary fashion, rostral M1 is most strongly connected with VLa, but it is also connected with VLp. VLx, a target of cerebellar projections, has significant connections with both caudal and rostral M1. These results indicate that all parts of M1 are influenced by both the cerebellum and globus pallidus in owl monkeys, as has been suggested in some recent studies of macaque monkeys. © 1994 Wiley‐Liss, Inc.
Cellular retinol‐binding protein type I is prominently and differentially expressed in the sensory epithelium of the rat cochlea and vestibular organs
Authors: Ylikoski Jukka , Pirvola Ulla , Eriksson Ulf 
Published: January 2005

AbstractTo understand the possible role of retinoic acid during inner ear development and cellular regeneration, we have examined the expression pattern of two intracellular retinoid‐binding proteins, the cellular retinol‐ and retinoic acid‐binding proteins of type I in the developing and mature rat inner ear. Expression of cellular retinol‐binding protein type I was seen in the supporting cells of the organ of Corti and vestibular organs as soon as the first signs of differentiation of the adjacent hair cells were seen. In the developing organ of Corti, the expression pattern followed the basal‐to‐apical coil differentiation gradient. After the 1st postnatal week, detectable expression of cellular retinol‐binding protein type I disappeared from the organ of Corti, but persisted in the supporting cells of vestibular organs throughout life. Expression of cellular retinoic acid‐binding protein type I was not found in the inner ear sensory epithelia. Cellular retinol‐binding protein type I has previously been shown to act as a substrate carrier in the synthesis of retinoic acid from its precursor, retinol. Our data suggest that retinoic acid is synthesized in the developing sensory epithelium of the cochlear and vestibular organs and that a concentration gradient formed by retinoic acid may have a role in differentiation of the cochlear sensory epithelium. Furthermore, retinoic acid may have a role in damage‐induced hair cell regeneration in the developing and mature vestibular organs as well as in the developing auditory organ. The absence of cellular retinol‐binding protein type I from the supporting cells of the mature organ of Corti may be associated with the inability of this organ to regenerate hair cells after damage. © 1994 Wiley‐Liss, Inc.
Postnatal development of the hamster cochlea. II. Growth and differentiation of stereocilia bundles
Authors: Kaltenbach James A. , Falzarano Pamela R. , Simpson Thomas H. 
Published: January 2005

AbstractThe postnatal development of stereocilia was studied in the Syrian golden hamster. The purpose was to describe tae morphological changes underlying the differentiation of stereocilia bundles and to define the time course of their growth in different regions of the cochlea. Differentiation of the hair bundle occurred by progressive changes in stereocilia number, dimensions, and spatial relationships. The overall transformation of the bundle is interpreted as a four‐stage process involving the initial production of stereocilia (stage I), differentiation into tall and short populations (stage II), formation of distinct ranks (stage III), and resorption of excess stereocilia (stage IV). The orientation and arrangement of stereocilia during stage II began to occur before the tectorial membrane grew over the hair cell field.Growth in the dimensions of stereocilia occurred continuously throughout these four stages with increases in length and width occurring simultaneously. The time frame of the growth process depended both on location along the organ of Corti and on the type of hair cell. Hair bundles in the basal turn began growing and reached maturity a few days earlier than those in the apical turn. Stereocilia of outer hair cells matured earlier than those of inner hair cells. Outer hair cell stereocilia reached their adult lengths by 14 days after birth, those of inner hair cells between 16 and 18 days after birth. A kinocilium was present on almost all hair cells on the day of birth, but most were eliminated by 14 days after birth. Tip links were observed as early as 4 days after birth, and their growth appeared to be synchronous with the growth of stereocilia. The spatial gradient of stereocilia length, which increased toward the apex in the adult, was nearly the reverse of that seen at birth. The gradient for inner hair cells was associated with a gradient in the rate of stereocilia growth. The data further expand the foundation for interpreting mechanisms underlying the morphogenesis of stereocilia bundles in mammals and for understanding structure—function relationships during development. © 1994 Wiley‐Liss, Inc.
Central processing of sex pheromone, host odour, and oviposition deterrent information by interneurons in the antennal lobe of female Spodoptera littoralis (Lepidoptera: Noctuidae)
Authors: Anton Sylvia , Hansson Bill S. 
Published: January 2005

AbstractPhysiological and anatomical characteristics of antennal lobe interneurons in female Spodoptera littoralis (Boisd.) were investigated using intracellular recording and staining techniques. Responses of local interneurons and projection neurons to female sex pheromone components, host plant odours, and behaviourally active oviposition deterrents were recorded. We found local interneurons and projection neurons that responded specifically to only one or two of the tested odours, but we also found less specific cells, and neurons that responded to most of the tested odourants. These findings show that there are not only specific olfactory pathways in female moths up to the protocerebral level, but also that integration can begin in the antennal lobe. No correlation was found between the degree of specificity of either local interneurons or projection neurons and their respective morphological characteristics. Specialized and unspecialized local interneurons arborized throughout the antennal lobe. Specialized and unspecialized projection neurons had uniglomerular arborizations in the antennal lobe and sent their axons to the calyces of the mushroom body, and to the lateral horn of the protocerebrum. One specific projection neuron had multiglomerular arborizations and projected only to the lateral horn of the protocerebrum. Projection neurons arborizing in the glomeruli closest to the entrance of the antennal nerve always responded to pheromone components. No other correlations were found between the arborization pattern of projection neurons in the antennal lobe or in the protocerebrum and their response characteristics. The sensitivity of local interneurons and projection neurons was in the same range as that of receptor neurons in olfactory sensilla on the antennae, suggesting a much lower convergence in the central nervous system in females than in the pheromone‐processing pathway in males. © 1994 Wiley‐Liss, Inc.
Acetylcholinesterase activity in neurons of crayfish abdominal ganglia
Authors: Braun Götz , Mulloney Brian 
Published: January 2005

AbstractAcetylcholine is known to be a neurotransmitter in crustacean central nervous systems, but the numbers and distribution of cholinergic neurons in the segmental ganglia have not been described. To begin a census of cholinergic neurons in these ganglia, we used a histochemical assay for acetylcholinesterase to map neurons that contained this enzyme in the six abdominal ganglia of crayfish.In each abdominal ganglion, about 47 cell bodies were stained. The distributions of these stained cells in individual ganglia were similar, and the numbers were not significantly different. None of these stained cell bodies could be identified from their structures or locations as previously identified motor neurons or sensory neurons with central cell bodies. The process of one unpaired midline neuron that occurred only in the first three abdominal ganglia divided to send a pair of axons anteriorly into both halves of the connective.The central projections of afferent axons from many peripheral sensory neurons stained clearly as they entered each ganglion. Terminals of these axons were heavily stained in the horseshoe neuropil and the lateral neuropils.We labeled both γ‐aminobutyric acid (GABA) and acetylcholinesterase in individual ganglia. Only a few neurons in each ganglion were double‐labeled. The unpaired midline neurons in the three anterior ganglia that stained for acetylcholinesterase did not show GABA‐like immunoreactivity, but cells with similar shapes did label with the GABA antiserum.Acetylcholinesterase is not a definitive marker of cholinergic neurons, but its presence is often associated with the cholinergic phenotype. These stained cells should be considered as putative cholinergic neurons. © 1994 Wiley‐Liss, Inc.
Distribution of thyrotropin‐releasing hormone (TRH)‐containing cells and fibers in the human hypothalamus
Authors: Fliers Eric , Noppen Nicolette W. A. M. , Wiersinga Wilmar M. , Visser Theo J. , Swaab Dick F. 
Published: January 2005

AbstractIn the present study, we describe for the first time the distribution of thyrotropin‐releasing hormone (TRH)‐containing cells and fibers in the human hypothalamus using brain material obtained with a short postmortem delay. Following fixation in paraformaldehyde, glutaraldehyde and picric acid, excellent staining was obtained with two different TRH antisera. Many TRH‐containing neurons were present in the paraventricular nucleus (PVN), especially in the dorsocaudal part of this nucleus. They were mostly parvicellular, but a few magnocellular TRH‐positive neurons were observed as well. The PVN also contained a dense network of TRH fibers. The supraoptic nucleus (SON) did not show any TRH immunoreactivity, excluding the possibility of cross‐reactivity of the antiserum with neurohypophysial hormones or their precursors. In addition, TRH cells were found in the suprachiasmatic nucleus (SCN), which is the circadian clock of the brain, in the sexually dimorphic nucleus (SDN) and dorsomedially of the SON. We observed small numbers of TRH cells throughout the hypothalamic gray in all subjects studied.A high density of TRH‐containing fibers was seen not only in the median eminence but also in other hypothalamic areas, e.g., in the ventromedial nucleus (VM) and in the perifornical area. The results generally agree with earlier data in the rat, with the exception of the absence of TRH cells in the SON. The large number of sites of TRH‐containing fiber terminations on neurons suggests important physiological functions of this neuropeptide as a neurotransmitter or neuromodulator in the human brain in addition to its role as a neurohormone in pituitary secretion of thyroid‐stimulating hormone (TSH).
Embryonic development of the stomatogastric nervous system in Drosophila
Authors: Hartenstein Volker , Tepass Ulrich , Gruszynski‐Defeo Eileen 
Published: January 2005

AbstractUsing several cell‐specific markers, the pattern of proliferation, morphogenesis, and neuronal differentiation of the Drosophila larval stomatogastric nervous system (SNS) was analyzed. In the late embryo, four SNS ganglia (frontal ganglion, hypocerebral ganglion, paraesophageal ganglion, ventricular ganglion) can be distinguished. In the early embryo, the precursor cells of the SNS (SNSPs), being an integral part of the anlage of the esophagus, undergo four synchronous rounds of division. Subsequently, SNSPs segregate from the esophageal epithelium in a complex and stereotyped pattern. The majority of SNSPs invaginate and transiently form three (rostal, intermediate, caudal) pouches that, after separating from the esophagus, become epithelial vesicles. At later stages, these SNSPs gradually lose their epithelial phenotype. Starting at the anterior‐dorsal tip of each vesicle, SNSPs dissociate from one another and migrate to the various locations where they differentiate as neurons. Cells of the rostral and intermediate vesicle contribute to the frontal ganglion; the hypocerebral ganglion develops from the intermediate vesicle, the paraesophageal ganglion from the rostral vesicle, and the ventricular ganglion from the caudal vesicle. In addition to the invaginating SNSPs, several distinct groups of SNSPs delaminate as individual cells from the esophageal epithelium. Three clusters of SNSPs delaminate from a region anterior to the rostral pouch; a single SNSP delaminates from the tip of each pouch. All delaminates from the tip of each pouch. All delaminating SNSPs contribute to the frontal ganglion. A significant number of SNSPs undergo cell death. In the late embryo, the stomatogastric ganglia are interconnected by the recurrent nerve and esophageal nerves. The frontal ganglion projects to the brain via the frotal connectives. Both recurrent nerve and frontal connectives are pioneered by small subpopulations of early differentiating stomatogastric neurons that most likely derive from among the dSNSPs and iSNSPs.
Hair and supporting‐cell differentiation during the development of the avian inner ear
Authors: Goodyear Richard , Holley Matthew , Richardson Guy 
Published: January 2005

AbstractTwo monoclonal antibodies and serial section analysis have been used to compare the sites and times at which hair and supporting‐cells differentiate in various sensory regions of the chick inner ear during its development. A monoclonal antibody recognising the 275 kD hair‐cell antigen, a protein that is specifically associated with the apical surface of hair cells, was used to identify immature hair cells. Another monoclonal antibody, gm‐2, which stains the gelatinous membranes of the cochlear duct, sacculus, and utriculus and the epithelial supporting cells of all vestibular structures in the inner ears of early posthatch chicks, was used to detect the onset of supporting‐cell differentiation. Although the antigens recognised by the two antibodies are first detected almost simultaneously during the development of each sensory region, their appearance is not always exactly temporally coincident, and their order of appearance, when not coincident, varies between the epithelia but is always the same within any one organ. Also, when the two antigens are first present in any one region, there is not always a very precise overlap in their spatial distribution. These results cannot be explained entirely by a previously proposed model for hair and supporting‐cell development in which hair cells differentiate first and prevent undetermined, surrounding cells from becoming hair cells via lateral inhibition. Modified forms of the original model that can accommodate some of these observations are considered and discussed. © 1995 Willy‐Liss, Inc.
Innervation of the hard palate in the rat studied by anterograde transport of horseradish peroxidase conjugates
Authors: Arvidsson J. , Fundin B. T. , Pfaller K. 
Published: January 2005

AbstractThe innervation of the rat hard palate and the bordering part of the soft palate was studied after anterograde transport of horseradish peroxidase conjugated to wheat germ agglutinin (WGA‐HRP) and to choleragenoid (B‐HRP) in separate experiments. WGA‐HRP labeling showed leakage from several types of nerve endings, whereas B‐HRP did not. Both conjugates gave rise to heavy labeling of a variety of nerve endings. Intragemmal and, especially, perigemmal fibers were labeled in chemosensory corpuscles, which were most common in the medial wall of the incisive canal and in the most anterior part of the soft palate. Ruffini endings of different sizes were labeled in the incisive papilla. Other subepithelial endings forming elongated expanded profiles with medium‐to large‐caliber source fibers were most common in protruding parts of the palate. Labeled intraepithelial endings included Merkel endings, which were most frequent in the incisive papilla and the rugae. Other labeled profiles were medium‐caliber afferents giving rise to irregular, beaded, and sometimes branched endings often located far superficially in the epithelium. Such endings were present both within and between protruding parts of the palate. Fine‐caliber intraepithelial endings were labeled almost exclusively in WGA‐HRP experiments. © 1995 Willy‐Liss, Inc.
Distribution of four types of synapse on physiologically identified relay neurons in the ventral posterior thalamic nucleus of the cat
Authors: Liu X.‐B. , Honda C.N. , Jones E.G. 
Published: January 2005

AbstractThis study was aimed at providing quantitative data on the thalamic circuitry that underlies the central processing of somatosensory information. Four physiologically identified thalamocortical relay neurons in the ventral posterior lateral nucleus (VPL) of the cat thalamus were injected with horseradish peroxidase and subjected to quantitative electron microscopy after pre‐ or postembedding immunostaining for γ‐aminobutyric acid to reveal synaptic terminals of thalamic inhibitory neurons.The four cells all had rapidly adapting responses to light mechanical stimuli applied to their receptive fields, which were situated on hairy or glabrous skin or related to a joint. Their dendritic architecture was typical of cells previously described as type I relay cells in VPL, and they lacked dendritic appendages.Terminals ending in synapses on the injected cells were categorized as RL (ascending afferent), F (inhibitory), PSD (presynaptic dendrite), and RS (mainly corticothalamic) types and were quantified in reconstructions of serial thin sections. RL and F terminals formed the majority of the synapses on proximal dendrites (approximately 50% each). The number of synapses formed by RL terminals declined on intermediate dendrites, but those formed by F terminals remained relatively high, declining to moderate levels (20–30%) on distal dendrites. RS terminals formed moderate numbers of the synapses on intermediate dendrites and the majority (< 60%) of the synapses on distal dendrites. Synapses formed by PSDs were concentrated on intermediate dendrites and were few in number (∼6%). They formed synaptic triads with F terminals and rarely with RL terminals. On somata, only a few synapses were found, all made by F terminals.The total number of synapses per cell was calculated to be 5,584–8,797, with a density of 0.6–0.9 per micrometer of dendritic length. Of the total, RL terminals constituted approximately 15%, F terminals approximately 35%, PSD terminals approximately 5%, and RS terminals approximately 50%. These results provide the first quantitative assessment of the synaptic architecture of thalamic somatic sensory relay neurons and show the basic organizational pattern exhibited by representatives of the physiological type of relay neuron most commonly encountered in the VPL nucleus. © 1995 Wiley‐Liss, Inc.