bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial organization of inner hair cell synapses and cochlear spiral ganglion neurons
Authors: Leake Patricia A. , Snyder Russell L. , Hradek Gary T. 
Published: January 2005

AbstractThe morphological organization of the central projections of the cat cochlear spiral ganglion into the cochlear nucleus was previously investigated by creating restricted lesions in the anteroventral cochlear nucleus (AVCN) to ablate selectively either the lateral or the medial aspect of isofrequency projection laminae. Such lesions resulted in highly selective retrograde degeneration of spiral ganglion cells. Ablation of the lateral part of the AVCN caused degeneration of cells within the scala tympani part of the ganglion, whereas medial ablations within the AVCN induced degeneration of the scala vestibuli aspect of the ganglion. The peripheral axons also degenerated and this fiber loss exhibited selective topographies that paralleled the cell loss within the spiral ganglion, although this phenomenon was more prominent in the proximal part of the osseous spiral lamina near the ganglion and less obvious more distally near the habenula perforata.In this investigation, inner hair cells (IHCs) from these selective lesion cases were evaluated by electron microscopy of serial sections through the basal synaptic regions. Results demonstrated differential degeneration of afferent synapses, with greater (but not completely selective) loss of pillar synapses after lateral AVCN lesions and greater loss of modiolar synapses after medial lesions. Because auditory nerve fibers of different spontaneous discharge rates (SRs) have different spatial distributions on the IHC (Liberman, Science 216:1239, 1982), our results suggest that this SR‐based organization is maintained in a topographic organization across the vertical (scala tympani‐to‐scala vestibuli) dimension of the spiral ganglion cell cluster and carried into the ventral cochlear nuclei (VCN). Thus, in addition to the spiral frequency organization represented by the dorsal‐to‐ventral frequency map in the VCN, there is also an orderly organization of inputs from high‐ and low‐SR fibers across the lateral‐to‐medial dimension of the VCN such that the lateral isofrequency laminae receive a proportionately greater input from high‐SR fibers, whereas medial isofrequency laminae receive preferential input from low‐ and medium‐SR fibers. © 1993 Wiley‐Liss, Inc.
Histoautoradiographic detection of oxytocin‐ and vasopressin‐binding sites in the telencephalon of the rat
Authors: Krémarik Pascaline , Freund‐Mercier Marie‐José , Stoeckel Marie‐Elisabeth 
Published: January 2005

AbstractLocalization of oxytocin‐ and vasopressin‐binding sites has so far been studied in the rat brain by means of film autoradiographs. The disposal of iodinated ligands with high specificity has allowed us to develop histoautoradiography on emulsion‐coated sections and to reinvestigate on a microscopic scale the distribution of these sites in the telencephalon (septum, striatopallidal system, amygdala and hippocampus). This technique showed that oxytocin and vasopressin labelling presented distinct distributions and coincided with delimited zones, corresponding to anatomical subdivisions defined on cytoarchitectural and immunocytochemical bases. Vasopressin sites were seen in the dorsal and intermediate parts of the lateral septum and the juxtacapsular nucleus of the bed nucleus of the stria terminalis. Oxytocin sites were located in the ventral and intermediate parts of the lateral septum, the oval and the principal nuclei of the bed nucleus of the stria terminalis and the septofimbrial nucleus. In the striatopallidal system, vasopressin sites were found in the accumbens nucleus and the fundus striati, whereas oxytocin sites were in the accumbens nucleus, the head, and the posterolateral parts of the caudate‐putamen, the striatal cell bridges, and the olfactory tubercle. In the amygdala, vasopressin sites were not found, but oxytocin sites were located in the central, medial, and basomedial nuclei. In the hippocampus, vasopressin sites were located in the dentate gyrus (polymorph and molecular layers), and oxytocin sites, in the subiculum (molecular and pyramidal layers) and in the field CA1 of Ammon's horn (lacunosum moleculare and pyramidal layers). The localization of the binding sites at the microscopic level permitted us to reinvestigate whether or not correlation existed in a same area between innervation, electrophysiological effects, and presence of binding sites. © 1993 Wiley‐Liss, Inc.
Localization and differential expression of FMRFamide‐like immunoreactivity in the nematode Ascaris suum
Authors: Cowden Cynthia , Sithigorngul Paisarn , Brackley Philip , Guastella John , Stretton Antony O. W. 
Published: January 2005

AbstractBy immunocytochemical and immunohistochemical methods, FMRFamide‐like immunoreactivity (FLI) was localized to many neurons and processes in the Ascaris nervous system, including the head, tail, and lateral lines. Some of these cells were identified; they included sensory neurons, interneurons, and motor neurons. FLI was also present in the pharyngeal neurons and in their varicosities near the surface of the pharynx. By HPLC analysis of extract, only a subset of the FMRFamide‐like peptides (FLPs) expressed in Ascaris heads, and heads from which the pharynx had been removed, were expressed in the pharynx. Furthermore, FLPs appeared to be differentially expressed in female heads and tails and male heads and tails. Acetone and acid methanol differentially extracted subforms of FLI from Ascaris heads and from C. elegans. © 1993 Wiley‐Liss, Inc.
Golgi study of the telencephalon of the small‐spotted dogfish Scyliorhinus canicula L
Authors: Manso M. Jesús , Anadón Ramóan 
Published: January 2005

AbstractThe telencephalon of the small‐spotted dogfish, Scyliorhinus canicula L., was examined by Nissl and Golgi‐aldehyde techniques. On the basis of differences in perikaryal and dendritic morphology and size, several cell types were distinguished in pallial and subpallial regions, most of them reported here for the first time in elasmobranchs. In the pallium, the pallium dorsalis is the richest in cell types (eight types of neurons), whereas the neuron population of the pallium medialis is the most homogeneous. Dendrites of most neuron types in the pallium are smooth or sparsely thorny. Interestingly, the pallium dorsalis and pallium lateralis contain a type of primitive pyramidal cell characterized by the dense appearance of its thorny dendrites. In the subpallium, the area superficialis basalis contains a heterogeneous population (six types of neurons): large radial cells are the most characteristic cell type. Dendrites of these cell types are smooth or sparsely thorny. The cell populations of the nucleus N are roughly similar to those of the area superficialis basalis, but they lack the large radial cells characteristic of this area. The area centralis subpallialis and striatum consist of populations of small neurons. The regio septalis contains a rather homogeneous population of small cells. The populations in the nucleus entopeduncularis and the nucleus interstitialis of the basal forebrain bundle are the least varied and consist of large radial cells and bipolar cells similar to those of the area superficialis basalis. This investigation reveals important differences in cytoarchitecture that should be useful in the interpretation of immunocytochemical, tracing, and electrophysiological studies of the telencephalon of elasmobranchs. © 1993 Wiley‐Liss, Inc.
Increased serotoninergic innervation of the hamster's superior colliculus alters retinotectal projections
Authors: Rhoades Robert W. , Bennett‐Clarke Carol A. , Lane Richard D. , Leslie Michael J. , Mooney Richard D. 
Published: January 2005

AbstractAnterograde tracing with horseradish peroxidase (HRP) was used to compare the organization of retinotectal projections in normal adult hamsters and in animals that sustained subcutaneous injections of the neurotoxin 5,7‐dihydroxytryptamine (5,7‐DHT) on the day of birth. Neonatal injection of this neurotoxin decreases the density of the serotoninergic (5‐HT) innervation of the cerebral and cerebellar cortices, but increases the density of these fibers in the brainstem including the superior colliculus (SC). Analysis of tissue from the retinorecipient laminae of the SC by high‐pressure liquid chromatography indicated that these lesions increased the amount of 5‐HT in the adult SC by 47%. The increased serotoninergic innervation of SC was associated with a marked change in the distribution of the uncrossed retinotectal projection. In normal adult hamsters, fibers from the ipsilateral eye form dense clusters in the lowermost stratum griseum superficiale (SGS) and stratum opticum (SO). A small number of uncrossed fibers are also visible in the more caudal portions of these layers. In the animals that sustained neonatal 5,7‐DHT injections, uncrossed retinotectal fibers formed a nearly continuous band in rostral SO and lower SGS, and numerous labeled fibers were present in the caudal SC, primarily in the SO. Neonatal treatment with 5,7‐DHT also produced alterations in the crossed retinotectal pathway and in the crossed and uncrossed retinogeniculate projections. These results indicate that the 5‐HT input to the developing brainstem may strongly influence the development of retinofugal projections. © 1993 Wiley‐Liss, Inc.
Estrogen receptor‐immunoreactive forebrain neurons project to the ventrolateral hypothalamus in female guinea pigs
Authors: Delville Yvon , Blaustein Jeffrey D. 
Published: January 2005

AbstractIn rodents, the facilitation of sexual receptivity by estradiol and progesterone is suspected to be mediated by a network of neurons containing estrogen and progestin receptors. In female guinea pigs, this network would include estrogen receptor‐immunoreactive (ER‐ir) neurons located within the rostro‐ventral ventrolateral hypothalamus (r‐vVLH). This hypothesis predicts that a proportion of the neurons projecting to the r‐vVLH contains estrogen receptors. This prediction was tested through retrograde tracing combined with immunocytochemistry for estrogen receptors. Retrogradely labelled neurons were particularly abundant within the medial preoptic nucleus (MPN), bed nucleus of the stria terminalis (BST), anterior hypothalamus, amygdala, and lateral parabrachial nucleus. As predicted by the hypothesis, retrogradely labelled neurons were mostly observed in estrogen receptor‐rich areas. Retrogradely labelled neurons also containing estrogen receptor‐immunoreactivity (ER‐IR) were primarily found within the MPN, BST, and amygdala. However, a majority of retrogradely labelled neurons did not contain ER‐IR. As the preoptic area and the r‐vVLH are both responsive to estradiol in the facilitation of sexual receptivity by progesterone, these data are consistent with the hypothesis tested. However, our data also suggest that the network of neurons controlling sexual receptivity may include elements not directly sensitive to estradiol. Finally, the location of retrogradely labelled neurons is discussed with respect to the stimuli provided to the r‐vVLH in the context of sexual receptivity facilitated by estradiol and progesterone. © 1993 Wiley‐Liss, Inc.
Ultrastructure of serotonin‐immunoreactive terminals in the core and shell of the rat nucleus accumbens: Cellular substrates for interactions with catecholamine afferents
Authors: Van Bockstaele Elisabeth J. , Pickel Virginia M. 
Published: January 2005

AbstractThe nucleus accumbens is composed of a core region involved in motor functions and a shell region implicated in emotional and motivational processes. Both of these regions receive serotonin‐ and dopamine‐containing afferents. We examined whether the serotonin innervation or relation to catecholamine (mainly dopamine) axons in the nucleus accumbens shows common features or specializations corresponding to the noted functional differences in core and shell subregions. To address this question, we examined the ultrastructure of serotonin‐containing axons and their relation to catecholamine‐containing afferents in either the core or shell of the nucleus accumbens. Single coronal sections through the rat forebrain were processed for immunoperoxidase labeling of serotonin and immunogold silver labeling of tyrosine hydroxylase, the catecholamine‐synthesizing enzyme. Varicose processes showing peroxidase product for serotonin by light microscopy were confirmed to be axons and terminals by electron microscopy. In a quantitative analysis of serotonin‐immunoreactive terminals forming one or more contacts in single sections, some common features were observed. For the core (n = 120) and the shell (n = 82), 41% formed synaptic junctions with unlabeled dendrites, 75% were in apposition with unlabeled terminals, which often formed asymmetric junctions, and 20% were in apposition with axons or terminals containing tyrosine hydroxylase. Thus, in both the core and shell of the nucleus accumbens, serotonin terminals synapse on postsynaptic neurons and are likely to modulate or be modulated by presynaptic interactions with excitatory axons forming asymmetric junctions and by catecholaminergic afferents.Marked differences in the morphology of serotonin axons were also seen in the core versus shell of the nucleus accumbens. By light microscopy, serotonin‐immunoreactive axons were thicker and more varicose than those found in the core. Ultrastructural analysis confirmed that, in contrast to the core, serotonin‐immunoreactive axons and terminals in the shell were larger in cross‐sectional diameter size (0.7 μm vs. 0.3 μm). Additionally, serotonin axon terminals in the shell contained more numerous immunoreactive large dense core vesicles and more frequently formed symmetric as opposed to asymmetric contacts with dendrites. The larger size and more numerous dense core vesicles in serotonin‐immunoreactive terminals in the shell support the concept that serotonin or co‐existing neurotransmitter may be more tonically released in the shell versus core of the nucleus accumbens. © 1993 Wiley‐Liss, Inc.
Distribution of substance P‐like immunoreactivity in the brain of the elasmobranch Scyliorhinus canicula
Authors: Rodriguez‐Moldes Isabel , Manso Maria Jesus , Becerra Manuela , Molist Pilar , Anadon Ramon 
Published: January 2005

AbstractImmunohistochemical methods were used to study the distribution of substance P in the brain of the small‐spotted dogfish (Scyliorhinus canicula). Substance P‐like immunoreactive (SP‐IR) cell bodies and fibers were widely distributed. In the telencephalon, sparse populations ofSP‐IR neurons are present in the olfactory bulbs, pallium, and subpallium. In the subpallium numerous SP‐IR boutons form unusual coats (“pericellular appositions”) on SP‐immunonegative neurons. In the diencephalon numerous SP‐IR cerebrospinal fluid‐contacting neurons are present in the preoptic recess organ and organon vasculosum hypothalami. Numerous SP‐IR fibers also run in the hypothalamus, although no immunoreactivity was observed in the habenulo‐interpeduncular system. A terminal field of SP‐IR fibers is present in the median eminence. In the mesencephalic tegmentum, SP‐IR neurons were observed in the Edinger‐Westphal nucleus. SP‐IR fibers are present at high density in the basal tegmentum, forming a conspicuous tract. In the hindbrain, numerous SP‐IR fibers were observed in the isthmal region, the trigeminal descending root, the visceral sensory area and commissural nucleus, and the visceromotor column. SP‐IR fibers occur at high density in the substantia gelatinosa of the rostral spinal cord. © 1993 Wiley‐Liss, Inc.
Topography of cholinergic afferents from the nucleus basalis of meynert to representational areas of sensorimotor cortices in the rat
Authors: Baskerville Karen A. , Chang Howard T. , Herron Paul 
Published: January 2005

AbstractWe investigated (1) the topography of projection neurons in the nucleus basalis of Meynert (NBM) with efferents to restricted regions of the primary somatosensory (SI), the second somatosensory (SII), and the primary motor (MI) cortices in the rat; (2) the percentage of these NBM projection neurons that were cholinergic; and (3) the collateralization, if any, of single NBM neurons to different subdivisions within SI, to homotopic areas of SI and SII, and to homotopic areas of SI and MI. Retrograde single‐and double‐labeling techniques were used to study NBM projections to electrophysiologically identified subdivisions of SI and to homotopic representational areas of SI and SII, and of SI and MI. Choline acetyltransferase immunocytochemistry was done to identify cholinergic NBM neurons. Of the retrogradely labeled NBM neurons that projected to selective subdivisions of SI, SII, and MI, 89%, 87%, and 88%, respectively, were cholinergic. We found a rostral‐to‐caudal progression of retrogradely labeled NBM neurons following a medial‐to‐lateral sequence of injections into subdivisions of SI. Overlapping groups of single‐labeled NBM neurons were observed after injections of different tracers into adjacent subdivisions within SI or homotopic areas of SI and SII, and of SI and MI. We conclude that NBM innervation to SI, SII, and MI is mostly cholinergic in the rat, that each cortical area receives cholinergic afferents from neurons widely distributed within the NBM, and that each NBM neuron projects to a restricted cortical area without significant collateralization to adjacent subdivisions within SI or to homotopic areas of SI and SII, or SI and MI. © 1993 Wiley‐Liss, Inc.
Localization of cholecystokinin binding sites in the adult and developing Brazilian opossum brain
Authors: Kuehl‐Kovarik M. Cathleen , Ross Lynne R. , Elmquist Joel K. , Jacobson Carol D. 
Published: January 2005

AbstractCholecystokinin (CCK) is now recognized as one of the most abundant peptides in the mammalian central nervous system. We have previously used immunohistochemistry to localize CCK in the adult and developing Brazilian opossum brain. However, little is known about the distribution of CCK binding sites in the developing mammalian brain. Therefore, to further our knowledge of the sites of action for CCK during development, we initiated a series of studies to localize CCK binding sites in the adult and developing Brazilian opossum. This species was chosen because pups are born in a fetus‐like state. Receptor autoradiography was performed on coronally sectioned brains of 1 to 60 day postnatal (PN) animals and adults with 125I‐Bolton Hunter‐CCK‐8 as the radioligand. Binding is evident in the 1PN opossum brainstem and is observed in the developing forebrain by 5PN. Region‐specific binding increases during development, and binding in the 35PN brain resembles the adult pattern. Binding is evident prior to the detection of CCK‐like immunoreactivity in many areas. The facial motor nucleus is identifiable and exhibits high levels of binding in Brazilian opossum pups of 10 to 35 days of age. However, binding is undetectable in the facial motor nucleus of 45 and 60PN pups. In general, the binding patterns for CCK in the adult opossum resemble those of other mammals and likely mediate similar physiological functions. However, some cholecystokininergic pathways appear to be unique to neonatal mammals. © 1993 Wiley‐Liss, Inc.
Monosynaptic innervation of trigeminal motor neurones involved in mastication by neurones of the parvicellular reticular formation
Authors: Mogoseanu D. , Smith A. D. , Bolam J. P. 
Published: January 2005

AbstractIn order to determine whether neurones in the parvicellular reticular formation are in direct synaptic contact with motor neurones innervating masticatory muscles, a combined retrograde and anterograde transport study was carriedd out in the rat at both light and electron microscopic levels. The animals received injections of the retrograde tracers wheat germ agglutinin conjugated to horseradish peroxidase or cholera toxin B conjugated to horseradish peroxidase into the masticatory muscles and of the anterograde tracer biocytin into the ipsilateral parvicellular reticular formation. The trigeminal motor nucleus was then examined for both anterograde and retrograde labelling in the light and electron microscopes.Retrogradely labelled motor neurones were identified in the trigeminal motor nucleus. They were large and their locations within the nucleus depended on the muscle injected. In addition, terminals anterogradely labelled with the biocytin that was injected in the parvicellular reticular formation were identified throughout the motor nucleus. At the electron microscopic level, the retrogradely labelled cells were found to receive input both from distinct types of unlabelled terminals and from terminals that were anterogradely labelled from the parvicellular reticular formation. The labelled terminals comprised one of the four classes of afferent terminals, being 1–2 μm in diameter and densely packed with spherical vesicles. They formed mostly asymmetrical but also symmetrical synapses with the labelled perikarya and dendrites. Anterogradely labelled terminals were also observed to form both symmetrical and asymmetrical synaptic contacts with unlabelled structures in the motor nucleus.It is concluded that neurones in the parvicellular reticular formation form direct synaptic contact with motor neurones of masticatory muscles. This pathway may represent the anatmical substrate by which the reticular formation exerts at least part of its influence on mastication. Since the parvicellular reticular formation receives input from the substantia nigra pars reticulata, it is possible that this pathway represents a system whereby the basal ganglia directly influence orofacial movement. © 1993 Wiley‐Liss, Inc.