bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distinct subsets of sensory olfactory neurons in mouse: Possible role in the formation of the mosaic olfactory projection
Authors: Key Brian , Akeson Richard A. 
Published: January 2005

AbstractThe axons of the primary sensory olfactory neurons project from the olfactory neuroepithelium lining the nasal cavity, onto glomeruli covering the surface of the olfactory bulb. Neuroanatomical studies have shown previously that individual olfactory glomeruli are innervated by neurons that are dispersed widely within the nasal cavity. The aim of the present study was to test the hypothesis that phenotypically unique subsets of primary sensory olfactory neurons, scattered throughout the nasal cavity, project to a subset of glomeruli in specific olfactory bulb loci. Immunochemical and histochemical analyses in neonatal mice revealed that the plant lectin, Dolichos biflorus agglutinin, bound to a subset of mature primary sensory olfactory neurons which express the olfactory marker protein. This subset of neurons was principally located in the rostromedial and dorsal portions of the nasal cavity and projected specifically to a subset of glomeruli in the rostromedial and caudodorsal portions of the olfactory bulb. Analysis of Dolichos biflorus‐reactive axons revealed that these axons coursed randomly, with no evidence of their selective fasciculation, within the olfactory nerve. It was only at the level of the rostral olfactory bulb that a significant reorganisation of their trajectory was observed. Within the outer fibre layer of the bulb, discrete bundles of lectin‐reactive axons began to coalesce selectively into fascicles which preferentially oriented toward the medial side of the olfactory bulb. These data demonstrated that a phenotypically distinct subset of primary sensory olfactory neurons exhibits a topographical projection from the olfactory epithelium to the olfactory bulb, and suggests that these, and other subsets, may form the basis of the mosaic nature of this pathway. Moreover, it appears that the outer nerve fibre layer in the rostral olfactory bulb plays an important instructive role in the guidance and fasciculation of olfactory sensory axons. © 1993 Wiley‐Liss, Inc.
Regional specificities in the distribution, chemical phenotypes, and coexistence patterns of neuropeptide containing nerve fibres in the human anal canal
Authors: Hörsch Dieter , Fink Thorsten , Büchler Markus , Weihe Eberhard 
Published: January 2005

AbstractDespite the pivotal clinical significance of the human anal canal, little is known about its total and specific innervation. This study assessed the comparative distribution and histotopology of nerve fibres immunoreactive for neural markers and a variey of regulatory active neuropeptides in the human anal canal by light microscopic immunohistochemistry. Depending on the epithelial zone and region of the anal canal, the neural elements were differentially immunoreactive for the pan‐neural marker protein gene product 9.5, the catecholamine marker tyrosine hydroxylase, the neuroendocrine marker chromogranin A, and various neuropeptides. Protein gene product 9.5‐immunoreactive nerve fibres were ubiquitously abundant in the anal canal. In the anal transitional zone, ectopic epithelial types were supplied by the same pattern of peptidergic nerves as the respective type of epithelium in normotopic location. In the dermis of the squamous zone and in the perianal epidermis, unusual distribution patterns of nerve fibres, referred to as areas of high nerve fibre density, were encountered. Double immunohistochemistry revealed region‐specific coexistence patterns of neuropeptidergic nerve fibres, and novel peptide coexistence patterns were detected in anal nerve fibres. Subsets of nerve fibres formed close spatial relationships with chromogranin A‐positive neuroendocrine cells, most frequently in the anal transitional zone. Chromogranin‐A positive cells were shown to be present in the epithelium of perianal eccrine sweat glands. The differential distribution, peptide phenpotypes and coexistence patterns of different nerve fibre populations in the human anal canal may reflect topospecific regulatory functions of neurally released neuropeptides in health and disease. © 1993 Wiley‐Liss, Inc.
Immunocytochemical localization of glycine receptors in the mammalian retina
Authors: Grünert Ulrike , Wässle Heinz 
Published: January 2005

AbstractThe distribution of glycinergic synapses in the mammalian retina was studied with monoclonal antibodies against glycine receptors and a glycine receptor‐related protein (gephyrin). Monoclonal antibody 2b is specific for the α1 subunit of the glycine receptor; monoclonal antibody 4a is specific for all known α subunits and the β subunit, and monoclonal antibody 7a is specific for gephyrin.The three antibodies were applied to the retina of cat, macaque monkey, rat, and rabbit. The general staining pattern is comparable in all these species and it is similar but distinct with all of the three antibodies. Labeling is characterized by a punctate appearance indicating that it occurs at synapses. In the inner plexiform layer, labeling is concentrated in two bands. One band is located close to the inner nuclear layer; the other band is located in the middle of the inner plexiform layer. In the outer plexiform layer, sparse punctate labeling is seen.The distribution of gephyrin was also studied at the ultrastructural level in cat and monkey retina. Gephyrin is present on the postsynaptic membrane of amacrine cells and ganglion cells. The presynaptic profile to gephyrin immunoreactivity is always of an amacrine cell. The AII amacrine cell, the crucial glycinergic interneuron of the rod pathway, is presynaptic to gephyrin immunoreactivity in the OFF‐sublamina and is itself gephyrin‐positive at an input synapse from another (possibly GABAergic) amacrine cell in the ON‐sublamina. © 1993 Wiley‐Liss, Inc.
Location and completeness of reinnervation by two types of neurons at a single target: The feline muscle spindle
Authors: DeSantis Mark , Norman Wesley P. 
Published: January 2005

AbstractMuscle spindles from the tenuissimus muscle of the cat were examined microscopically to assess the precision and completeness of reinnervation of intrafusal muscle fibers by efferent and afferent neurons. Positions of motor and sensory nerve terminals were charted relative to the cross‐sectional area enclosed by the outer capsule of the spindle. Profiles of nerve endings were measured for normally innervated and reinnervated spindles. The tenuissimus was deprivedof innervation by freezing its nerve, sometimes in conjunction with either spinal ganglion removal or ventral rhizotomy. Sensory and motor terminals occupied separate locales along the length of normal muscle spindles. Nerve terminals of efferent and afferent neurons were located in appropriate positions along the length of spindles when axons of both types of neurons regrew‐together and when either category of axon regenerated alone. Precise reinnervation of muscle spindles occurred in spite of a diminished diameter of intrafusal fibers. Repopulation of the spindle with motor endings was less complete than that by sensory endings, based on the proportion and size of the regenerated terminals. We conclude that under optimal conditions for axonal regrowth, efferent and afferent neurons reinnervate their respective regions along intrafusal muscle fibers but motor lags sensory reinnervation within the spindle. The mechanism by which positional specificity happens during reinnervation of intrafusal fibers requires neither an interaction between terminals of the two types of neurons nor target cells of normal bulk. © 1993 Wiley‐Liss, Inc.
Crossed receptive field components and crossed dendrites in cat sacrocaudal dorsal horn
Authors: Gladfelter Wilbert E. , Millecchia Ronald J. , Pubols Lillian M. , Sonty Ramana V. , Ritz Louis A. , Covalt‐Dunning Dorothy , Culberson James , Brown Paul B. 
Published: January 2005

AbstractThe hypothesis that sacrocaudal dorsal horn neurons with crossed receptive field components on the tail have dendrites which cross to the contralateral dorsal horn was tested in a combined electrophysiological and morphological study. Dorsal horn cells in the sacrocaudal spinal cord of anesthetized cats were penetrated with horseradish peroxidase‐filled microelectrodes. After mapping their low threshold mechanoreceptive fields, cells were iontophoretically injected with horseradish peroxidase.A sample of 16 well‐stained cells was obtained in laminae III and IV. Cells with receptive fields crossing the dorsal midline of the tail (n ‐ 8) had somata in the lateral ipsilateral dorsal horn, and some of these cells (5/8) had dendrites which crossed to the lateral contralateral dorsal horn. Cells with receptive fields spanning the ventral midline (n ‐ 2) were located near the center of the fused dorsal horn, and one of these had bilateral dendrites in this region. Cells with receptive fields on the lateral tail, crossing neither the dorsal nor the ventral midline (n ‐ 6), had cell bodies in the middle of the ipsilateral dorsal horn; half had only ipsilateral dendrites, and half had crossed dendritic branches.Although the relationship between cell receptive field (RF) location (RF center, expressed as distance from tips of toes) and mediolateral location of the cell body was statistically significant, the correlation between crossed RF components and crossed dendritic branches was not significant. © 1993 Wiley‐Liss, Inc.
Neuropeptide Y immunoreactivity identifies a group of gamma‐type retinal ganglion cells in the cat
Authors: Hutsler Jeffrey J. , White Cheryl A. , Chalupa Leo M. 
Published: January 2005

AbstractGanglion cells within the cat retina have been traditionally grouped by morphological criteria into three major classes: alpha, beta, and gamma. The gamma‐type cells have been least well characterized, but the available evidence indicates that this class comprises a relatively heterogeneous population of neurons. In the present study we demonstrate that an antibody for neuropeptide Y (NPY) recognizes a subpopulation of about 2,000 gamma‐type ganglion cells.The NPY‐immunoreactive (IR) neurons project to the superior colliculus and to the C layers of the lateral geniculate nucleus as demonstrated by retrograde labeling with fluorescent tracers (fluorogold or rhodamine latex microspheres). Virtually all of these cells disappear following lesions of the optic nerve. The NPY‐IR ganglion cells were identified as gamma cells on the basis of soma size and dendritic branching patterns. The somas of these neurons are small (8–22 μm in diameter), and each cell is characterized by sparsely branching dendritic processes, usually extending into the middle third of the inner plexiform layer, the physiologically defined ON sublamina. These neurons are distributed across the entire retina, with the highest density at the area centralis. Within local regions of the retina, however, there was no indication that the NPY‐IR gamma cells are arrayed in a regular mosaic pattern. These results provide the first evidence that the gamma class of ganglion cells of the cat retina can be subdivided on the basis of immunocytochemical properties. © 1993 Wiley‐Liss, Inc.
Antennular projections to the midbrain of the spiny lobster. III. Central arborizations of motoneurons
Authors: Schmidt Manfred , Ache Barry W. 
Published: January 2005

AbstractThe central organization of antennular motoneurons in the brain of the spiny lobster, Panulirus argus, was analyzed by combining biocytin backfills with serial reconstructions of the antennular nerves and the brain. Eighty‐nine to 99 antennular motoneurons occur in each hemibrain. The somata of the motoneurons are distributed in a consistent pattern in two complex soma clusters, the ventral paired mediolateral cluster of the deutocerebrum and the dorsal unpaired median cluster of the tritocerebrum. The motoneurons arborize ipsilaterally in the lateral and median antennular neuropils and the tegumentary neuropil. The backfills indicate a minimum of five morphological types of motoneurons with different arborization patterns. The innervation pattern of the motoneurons, together with previously reported innervation patterns of antennular sensory afferents, suggest that the lateral antennular neuropil is a lower motor center driving local antennular reflexes in response to chemical and mechanical stimulation of the antennule, whereas the median antennular neuropil is a lower motor center for equilibrium responses. © 1993 Wiley‐Liss, Inc.
Cortical axon trajectories and growth cone morphologies in fetuses of acallosal mouse strains
Authors: Ozaki Hiroki S. , Wahlsten Douglas 
Published: January 2005

AbstractHereditary absence of the corpus callosum (CC) provides an ideal experiment of nature for exploring mechanisms of axon guidance. In this study the prenatal development of CC axons in the acallosal mouse strains BALB/cWah1 and 129/ReJ or J was compared with normal hybrid mice by using the lipophilic dyes Dil and DiA. A few l/LnJ mice were also examined. The time of emergence and growth rate of CC axons from four cortical regions (frontal, parietal, temporal, occipital) were normal in acallosai strains. Their CC axons arrived at midplane on schedule but then often looped back to form the longitudinal Probst bundle. The frequency of formation of the Probst bundle was highest for axons from frontal cortex, which arrived at midplane first, and lowest for occipital axons, which arrived last. Once a few CC axons found a path to the other side via the hippocampal commissure, those that arrived later then crossed relatively normally. Some axons from the Probst bundle also managed to traverse midine in this manner. When no CC axons crossed, almost all of them entered the Probst bundle and eventually left it within a few hours to proceed in the ipsilateralwhite matter, never turning back toward midplane. Growth cones approaching midplane ipsilaterally and those that had crossed midline and entered contralateral white matter, as well as CC axons in the Probst bundle, expressed a normal range of size and complexity. These results demonstrate that the problem with callosal agenesis resides not in the cells of origin or the axons or growth cones themselves but in the Substrates of axon guidance at the midsagittal plane. © 1993 Wiley‐Liss, Inc.
Spinal projections of pelvic visceral afferents of the rat: A calcitonin gene‐related peptide (CGRP) immunohistochemical study
Authors: Chung Kyungsoon , Lee Won T. , Park Mae J. 
Published: January 2005

AbstractLittle information is available concerning the pelvic visceral afferent system, in view of its terminal location in the spinal cord and its associated transmitter substances in the rat. By utilizing an immunostaining method to examine the transneuronal neurotransmitter depletion resulting from peripheral sensory nerve injury, the spinal projections of primary afferent fibers containing calcitonin gene‐related peptide (CGRP) and originating from pelvic viscera were studied in the lumbosacral spinal cord of the rat. After unilateral or bilateral pelvic nerve section, CGRP immunoreactivity in the lumbosacral spinal cord was decreased greatly in the sacral parasympathetic nucleus (SPN), the dorsolateral fasciculus, the medial border of the dorsal horn, the dorsal gray commissure (DGC), and the intermediate gray connecting the SPN and DGC. Fine structural analysis showed that the CGRP‐immunoreactive terminals made synaptic contact with dendrites and, rarely, with somata. Although there was some incidence of a synaptic contact between a CGRP‐IR terminal and a vesicle‐containing profile, definite evidence of axo‐axonal synapse has not been confirmed. These data indicate that CGRP‐containing pelvic visceral primary afferent fibers project to autonomic areas of the lumbosacral spinal cord by way of the pelvic nerve and make synaptic contact with dendrites and somata. © 1993 Wiley‐Liss, Inc.
Chandelier cells in the hippocampal formation of the rat: The entorhinal area and subicular complex
Authors: Soriano Eduardo , Martinez Albert , Fariñas Isabel , Frotscher Michael 
Published: January 2005

AbstractIn the present study we describe the characteristics of the chandelier cells in the rat entorhinal cortex and subicular complex by using the Golgi method and combined Golgi‐electron microscopic techniques. In the entorhinal cortex, chandelier cells were frequently stained in layers II/III. Two types of axonal complexes were noted. One had a preferential horizontal orientation and gave rise to terminals located in the upper portion of layers II/III. The second type of chandelier cell axon was observed in the medial entorhinal area, innervating the entire extent of layers II/III. In the subicular complex, chandelier cells were frequently stained in the parasubiculum, whereas only a few cells were found in the presubiculum. In both subfields, chandelier cell axons were restricted to layers II/III. In the subiculum, most chandelier cells were present in the stratum radiatum, giving rise to a descending axon that branched in the stratum pyramidale. Both the size and morphological features of the chandelier cell terminal portions were found to be region‐specific.Electron microscopically, the cell body and dendrites of gold‐toned chandelier cells displayed typical features of nonpyramidal cells, such as the presence of nuclear infoldings, symmetric and asymmetric synapses on the cell body, and moderate numbers of axon terminals covering the smooth dendritic surface. Five gold‐toned chandelier cell axonal complexes were analyzed at the fine structural level. In all parahippocampal regions, gold‐labeled axon terminals formed symmetric contacts with axon initial segments. Our results demonstrate the presence, morphological characteristics, and target selectivity of identified chandelier cells in the parahippocampal region of the rat. Together with previous data, these results suggest a wide distribution of this specialized type of cortical interneuron and indicate that it is a constant and essential component of inhibitory circuits in the cerebral cortex. The possible significance of chandelier cells for the circuits linking several subfields of the hippocampal formation is discussed. © 1993 Wiley‐Liss,Inc.
Terminal arborizations of olfactory nerve fibers in the glomeruli of the olfactory bulb
Authors: Hálasz Norbert , Greer Charles A. 
Published: January 2005

AbstractThe glomerulus of the olfactory bulb may serve as a fundamental organizational unit for odor representation. In this context, the axons of olfactory receptor cells with similar response spectra may converge in specific glomerlui. While the topography between the olfactory epithelium and the olfactory bulb glomeruli has been explored, the characteristics of primary afferent terminal fields within glomeruli are poorly understood. To explore this issue, reconstructions of the terminal arbors of single olfactory nerve (ON) fibers within glomeruli were carried out in the rat olfactory bulb at the light microscopic level. Tissue samples prepared with the Golgi‐EM technique resulted in distinct impregnation of limited subsets of individual ON fibers. Following camera lucida reconstruction, quantitative analyses were made on selected sets of ON fibers and on the glomeruli they invaded. Most ON fibers began to arborize only after penetrating the glomeruli to a mean depth of approximately 35.9 μm. The fibers gave rise to a complex arbor of branches that was limited in total length (mean 157.7 μm) and the number of en passant varicosities or terminal enlargements (mean = 8.1). The number of varicosities and terminal boutons was proportional to the total length of branches. Also, there was a statistically significant correlation between the total branch length and the area (μm2) encompassed by the total arbor. The intraglomerular region supplied by the terminal arbor of an individual ON fiber was generally restricted. Given the recent molecular specificity attributed to olfactory receptor cells, this may provide a morphological basis for selective processing of signals encoded by specific receptors in the olfactory epithelium. © 1993 Wiley‐Liss, Inc.
Taste and tactile responsiveness of neurons in the posterior diencephalon of the channel catfish
Authors: Lamb Charles F. , Caprio John 
Published: January 2005

AbstractMany teleosts possess an enlargement of the ventral diencephalon called the inferior lobe. In ostariophysine species (e.g., carps and catfishes), this region receives ascending fibers from the primary and secondary gustatory centers in the hindbrain. Extracellular unit activity was recorded from identified nuclei in the inferior lobe of the channel catfish to characterize taste and tactile responsiveness from the different nuclei associated with gustatory projections.Taste responses (to amino acids and nucleotides) were recorded from units in the nucleus centralis (nCLI), nucleus lobobulbaris (caudal portion—nLB, rostrolateral portion—rl nLB, and parvicellular portion—nLBp), and lateral thalamic nucleus (nLT), supporting the proposed gustatory role for these nuclei. Tactile responsiveness was distinct between different nuclei in the caudal inferior lobe. Units from the nCLI and nLB had lower spontaneous activity than those from other nuclei, and typically had receptive fields including the whole extraoral body surface, ipsilaterally. Units from the rl nLB and nLBp had receptive fields, often including both oral and extraoral surfaces, bilaterally, but rl nLB receptive fields typically included the whole body, while those from nLBp units were often restricted to the head and mouth.The apparent electrophysiological distinction between these nuclei, combined with their different connectivity patterns, suggest that the gustatory nuclei in the inferior lobe of channel catfish are involved in various different sensory processing mechanisms. © 1993 Wiley‐Liss, Inc.
Fiber pathways and branching patterns of biocytin‐labeled olivocochlear neurons in the mouse brainstem
Authors: Brown M. C. 
Published: January 2005

AbstractOlivocochlear neurons have somata in the superior olivary complex in the brainstem and project fibers to the cochlea. The purpose of the present study was to demonstrate the fiber pathways and branching patterns of olivocochlear fibers within the brainstem. Olivocochlear fibers were labeled by extracellular injections of biocytin into the cochlea of mice. The injections labeled two populations of olivocochlear fibers. Thin olivocochlear fibers arose from small somata of the lateral olivocochlear group located ipsilaterally in the lateral superior olive. Thick olivocochlear fibers arose from larger somata of the medial olivocochlear group located bilaterally in the periolivary nuclei. The lateral olivocochlear and medial olivocochlear fibers had similar courses but differed in their branching patterns. Branches from lateral olivocochlear fibers terminated near their somata of origin in the lateral superior olive or in the lateral vestibular nucleus. Branches from medial olivocochlear fibers terminated in the inferior vestibular nucleus or in the cochlear nuclear complex. A few branches from medial olivocochlear fibers projected to the contralateral side. Although they project primarily to the cochlea, olivocochlear neurons also give off branches to a variety of nuclei in the brainstem, thus involving auditory and non‐auditory nuclei in the olivocochlear reflex system. © 1993 Wiley‐Liss,Inc.