bluuebunny/crossref_metadata_2025_split huggingface dataset:
Localization of serotonin immunoreactivity in the opossum cerebellum
Authors: Bishop Georgia A. , Ho Raymond H. , King James S. 
Published: January 2005

AbstractWe have used the indirect antibody peroxidase‐antiperoxidase technique to analyze (1) the course of serotonin (5‐hydroxytryptamine; 5HT) fibers to the deep cerebellar nuclei; (2) the distribution of serotonin within the nuclei; (3) the continued course of 5HT fibers to the cerebellar cortex; and (4) the lobular and laminar distribution of this indoleamine in the cerebellar cortex. Only rarely are fibers found in either the restiform body or the brachium pontis. However, a distinct bundle of serotoninergic axons is present in the medial aspect of the brachium conjunctivum. Axons arise from this bundle and course dorsally into the neuropil of the deep cerebellar nuclei. The densest immunostaining is present in posterior and ventral regions of all four cerebellar nuclei. Within the nuclei large (24% of total) and small (76% of total) varicosities are present. The average distance between varicosities on individual axons is 3.85 μm (S.D. = 1.2). The innervation of the cerebellar cortex is derived primarily from fibers that course through the deep nuclei. At levels caudal to the deep nuclei a single midsagittal band courses into lobules VIII and IX.In the cerebellar cortex, serotoninergic axons and varicosities are present in all lobules; however, the fiber density is not uniform. The densest distribution is present in vermal lobule VIII and the dorsal folia of lobule IX. Within the granule cell layer of lobules VIII and IX, immunoreactive elements form a midsagittal band, and to a lesser degree, two parasagittal bands. Beaded serotoninergic fibers course through the deep and middle portion of the granule cell layer and give rise to a plexus at the border between the Purkinje cell and granule cell layers. Within this plexus axons extend long distances in the transverse and sagittal planes. Long beaded axons oriented in the transverse plane of the folia are also present in the deep molecular layer. A few radial serotoninergic fibers ascend to the pial surface and give rise to very short tangential branches. In all three cortical layers, both large (19% of total) and small (81% of total) varicosities are present. The average distance between varicosities on individual fibers is 5.3 μm (S.D. = 2.2).In summary, these data have shown that (1) serotoninergic fibers enter the cerebellum via the brachium conjunctivum and form a dense plexus within the deep cerebellar nuclei; (2) there is a differential distribution of serotonin within these nuclei; (3) serotoninergic fibers pass through the deep nuclei and are topographically organized in their course to specific regions of the cerebellar cortex; (4) there is a differential distribution of serotonin to the various cortical lobules; (5) the densest distribution of serotonin within the cortex is to the Purkinje‐cell‐granule‐cell border; little immunoreactiveity is present in the molecular layer; and (6) this distribution is species specifie.
Morphology and laminar organization of electrophysiologically identified neurons in the primary auditory cortex in the cat
Authors: Mitani Akira , Shimokouchi Minoru , Itoh Kazuo , Nomura Sakashi , Kudo Motoi , Mizuno Noboru 
Published: January 2005

AbstractThe morphology of electrophysiologically identified neurons was examined in the primary auditory cortex (AI) of the cat. After stimulation of the medial geniculate nucleus (MG), second auditory cortex, posterior ectosylvian gyrus, contralateral AI, or corpus callosum, intracellular potentials were recorded from AI neurons, which were then injected intracellularly with horseradish peroxidase and recovered.Layer IV neurons, which receive MG fibers monosynaptically, are spiny and nonspiny stellate cells, small and medium‐sized nonspiny tufted cells, and fusiform cells. They send their axons to layer III of the AI. Corticocortical AI neurons are medium‐sized pyramidal cells in layer III. They receive axons from layer IV neurons of the AI and send their axons to layers I, II, IV, and V of the AI. Horizontal cells in layer I receive slow‐conducting MG fibers monosynaptically, and send their axons to layer II of the AI. Stellate cells and small pyramidal cells in layer II receive afferent inputs polysynaptically from the MG. Layer II pyramidal cells receive afferent inputs from the MG via AI neurons in layers I and III, and send their axons to layers V and VI. The axons of layer II stellate cells were distributed within layer II. Pyramidal cells which send their axons to the MG are located in layers V and VI, distributing their axon collaterals to layers III–VI of the AI.
Trigeminal mesencephalic neurons innervating functionally identified muscle spindles and involved in the monosynaptic stretch reflex of the lateral pterygoid muscle of the guinea pig
Authors: Nozaki Shuichi , Iriki Atsushi , Nakamura Yoshio 
Published: January 2005

AbstractLocation of the neurons in the trigeminal mesencephalic nucleus innervating stretch receptors of the lateral pterygoid muscle and the mode of their synaptic connection on the lateral pterygoid motoneurons of the guinea pig were studied physiologically as well as morphologically, in comparison with the trigeminal mesencephalic neurons innervating muscle spindles in the superficial masseter muscle, with the following results: (1) stimulation of the caudal half of the trigeminal mesencephalic nucleus evoked monosynaptic excitatory postsynaptic potentials in the ipsilateral lateral pterygoid motoneurons. (2) Stimulation of the lateral pterygoid nerve directly evoked spike potentials in the neurons located in the caudal half of the ipsilateral trigeminal mesencephalic nucleus, which responded with increased firing to stretch, and with silent period to twitch, of the ipsilateral lateral pterygoid muscle. (3) Averaging of intracellular potentials of the lateral pterygoid motoneurons with extracellular spike potentials of these trigeminal mesencephalic neurons revealed excitatory postsynaptic potentials after a monosynaptic latency, but no inhibitory postsynaptic potentials. (4) Injection of horseradish peroxidase into the lateral pterygoid muscle labeled 15–20 cells in the caudal half of the ipsilateral trigeminal mesencephalic nucleus, while 174–228 cells retrogradely labeled by horseradish peroxidase were found throughout the whole rostrocaudal extent of the ipsilateral trigeminal mesencephalic nucleus following injection of horseradish peroxidase into the masseter muscle. It was concluded that neurons in the caudal half of the trigeminal mesencephalic nucleus send their peripheral processes to stretch receptors, presumably muscle spindles, in the ipsilateral lateral pterygoid muscle and that their central processes have excitatory synapses on ipsilateral lateral pterygoid motoneurons, thus comprising the afferent limb of a monosynaptic stretch reflex arc of the lateral pterygoid muscle of the guinea pig.
Topography of the retinal projection to the superficial pretectal parvicellular nucleus of goldfish: A cobaltous‐lysine study
Authors: Springer Alan D. , Mednick Adam S. 
Published: January 2005

AbstractThe retinal projection to the superficial pretectal parvicellular nucleus (SPp) of goldfish was examined by filling select groups of optic axons with cobaltous‐lysine. The tracer was applied intraocularly to peripheral retinal slits in some fish. In other fish, it was applied to optic axons from an intact hemiretina after one‐half of the retina was ablated and the corresponding optic axons had degenerated. The results indicated that SPp is a folded structure, having a dorsal surface innervated by axons from temporal retinal ganglion cells and a ventral surface innervated by axons from nasal retinal ganglion cells. Peripheral retina innervates the anterodorsal and anteroventral edges of SPp, while central retina innervates the posterior genu. Dorsal retina innervates lateral SPp and ventral retina innervates medial SPp. Thus, although SPp is a folded nucleus, the topography of the retino‐SPp projection is similar to the topography of the retinotectal projection. That is, the relative position of optic axons within SPp mirrors the retinal location of the ganglion cells that project to SPp. Retino‐SPp axons occupy the center of the main optic tract before it divides into the two optic brachia. These axons are topographically arranged, with temporal retino‐SPp axons being flanked on both sides by nasal retino‐SPp axons. Retino‐SPp axons arborize within SPp and then continue to enter the superficial tectal retinorecipient lamina. Thus, these axons innervate both SPp and the optic tectum. These findings are discussed with respect to chemospecific and morphogenetic views of visual system topography.
Substance P‐like immunoreactivity is present in the central nervous system of Limulus polyphemus
Authors: Mancillas Jorge R. , Selverston Allen I. 
Published: January 2005

AbstractThe distribution of substance P‐like immunoreactivity (substance P‐li) in the central nervous system of Limulus polyphemus was studied by using indirect immunocytochemical techniques. Six bilaterally symmetrical pairs of cell clusters in the circumesophageal connectives and the subesophageal mass contain substance P‐li. Two of those pairs are the source of a system of efferent fibers that is involved in the expression of circadian rhythms of photosensitivity by the lateral eye. Substance P‐li‐containing cells were also observed scattered along the length of the circumesophageal connectives, which contain abundant stained fibers and some terminals. Substance P‐li fibers leave through the ventral and dorsal nerves of the posterior circumesophageal ring. The neuropil of the subesophageal mass contains an abundance of stained terminals. Immunoreactive fibers can be seen throughout the length of the two longitudinal connectives of the ventral cord, in discrete fiber tracts in the lateral edges of the interganglionic connectives, and in the dorsal and ventral nerves of abdominal ganglia 1–4. Each of these ganglia contains three pairs of 3ubstance P‐immunoreactive cell body clusters: an anterolateral, a medial longitudinal, and a medial posterior cluster. Substance P‐li fibers entering through the ventral (posterior) nerves form very distinctive fascicles in each side of the ganglia, giving off fibers throughout their length. The neuropil is filled with immunoreactive terminals distributed homogeneously.The anterolateral clusters of the abdominal ganglia may be involved in cardioregulation The six pairs of clusters in the posterior circumesophageal ring, and perhaps some of those in the abdominal ganglia, are believed to constitute a neurosecretory system, projecting to multiple targets throughout the organism. This system is postulated to modulate various sensory inputs and motor activity, and could be driven by a circadian clock, as well as by other systems responsible for integrated organismic responses.
The afferent and sympathetic components of the lumbar spinal outflow to the colon and pelvic organs in the cat. II. The lumbar splanchnic nerves
Authors: Baron R. , Jäunig W. , McLachlan Elspeth M. 
Published: January 2005

AbstractThe cell bodies of the lumbar sensory and sympathetic pre‐ and postganglionic neurons that project to the inferior mesenteric ganglion in the lumbar splanchnic nerves of the cat have been labeled retrogradely with horseradish peroxidase applied to the central end of their cut axons near the inferior mesenteric ganglion. The numbers, segmental distribution, location, and size of these labeled somata have been determined quantitatively. After all the lumbar splanchnic nerves on one side of an animal were labeled, most labeled cell bodies were situated ipsilaterally in dorsal root ganglia, ganglia of the lumbar sympathetic trunk, and spinal cord segments L2–L5, with the maximum numbers in L3 and L4. A few labeled somata lay contra‐laterally or rostral to L2. After labeling of only one lumbar splanchnic nerve, the majority of cell bodies were found in the labeled segment, but a few were also present up to three segments rostral or caudal. These variations could always be attributed to extraspinal connections usually via the lumbar sympathetic trunk. Cross‐sectional areas of labeled afferent somata were small relative to those of the entire population of dorsal root ganglion cells. Preganglionic cell bodies were labeled in the intermediate gray matter extending from its lateral border ventrolaterally across to the central canal. Two regions of high density were observed: one laterally just medial to the edge of the white matter and the other lateral to the central canal. The dorsolateral group lay somewhat medial and caudal to the usual limits of the intermediolateral column. Labeled preganglionic neurons were on the average larger than the unlabeled cells in the inferior mesenteric ganglion, with the group lying medially being larger than those that were laterally positioned. From the data, it is estimated that about 4,600 afferent axons, about 4,600 preganglionic axons, and about 2,800 postganglionic axons travel in the lumbar splanchnic nerves to the inferior mesenteric ganglion of the cat.
Plasticity of acid phosphatase (FRAP) afferent terminal fields and of dorsal horn cell growth in the neonatal rat
Authors: Fitzgerald Maria , Vrbová Gerta 
Published: January 2005

AbstractPeripheral nerve section results in depletion of fluoride‐resistant acid phosphatase (FRAP) from the nerve terminals in the dorsal horn of the spinal cord (Schoenen et al., '68) and this has been used in the past to map the termination field of individual nerves (Rustioni et al., '71; Devor and Claman, '80). In the present study we show that a similar central depletion occurs following sciatic nerve section or crush in neonatal rats. Unlike adults, however, the area of depletion is rapidly filled by sprouting of FRAP‐containing afferent terminals from nearby intact peripheral nerves. The sprouting is extensive but never completely fills the depleted area. After nerve crush there is some recovery of FRAP from the sciatic nerve terminals themselves as well as from nearby nerve terminals. The source of recovered FRAP is demonstrated by resectioning or recrushing the nerves. The sprouting occurred when the sciatic was injured on day 1 but failed to take place when the injury was applied on or after day 10.Sciatic nerve section on day 1 also produces marked growth retardation of the ipsilateral dorsal horn gray matter that becomes more apparent as the rat matures. Nerve crush produces a less marked shrinkage that is slower in onset. If the nerve is crushed repeatedly, however, so that regeneration is prevented, the shrinkage is analogous to that following nerve section. No shrinkage occurs if the nerve is cut or crushed on day 10.The results show that separation of the spinal cord from its peripheral input at a critical stage in development results in disruption of the somatotopic organization of the C fibre afferent input to the dorsal horn and in slowing of growth of the dorsal horn gray matter.
Organization of motor pools supplying the cervical musculature in a cryptodyran turtle, Pseudemys scripta elegans. II. Medial motor nucleus and muscles supplied by two motor nuclei
Authors: Yeow M. B. L. , Peterson E. H. 
Published: January 2005

AbstractIn this paper we describe the medial motor nucleus of Pseudemys cervical spinal cord and the motor pools of three neck muscles that exhibit an unusual pattern of innervation. Cells of the medial motor nucleus form a longitudinal column at the dorsomedial gray/white border of the ventral horn from C1 through C8. In Nissl‐stained transverse sections they appear fusiform with prominent medially projecting dendrites; in HRP material these dendrites are seen to cross into the contralateral ventral funiculus. Medial nuclear cells vary in size (12–31 μm in diameter) and are often relatively large (>21 μm in diameter). They are significantly larger and more numerous in caudal than in rostral cervical segments.Medial nuclear cells supply three of the cervical muscles examined in this study: mm. retrahens capitis collique (RCCQ), testocervicis, and longus colli. These three muscles differ from other cervical muscles in Pseudemys and from vertebrate limb muscles in that they are supplied in parallel by two populations of motor neurons: the medial and ventral motor nuclei (cf. Yeow and Peterson, '86). Ventral nuclear cells supplying these three muscles are organized into a musculotopic pattern with m. testocervicis motor neurons most medial and m. RCCQ motor neurons lateral; in contrast, the location of medial nuclear motor neurons is invariant with respect to muscle position. HRP‐positive medial nuclear cells are sometimes smaller (m. testocervicis) but more often are as large or larger (mm. RCCQ and longus colli) than ventral nuclear cells supplying the same muscles, thus suggesting that they supply extrafusal muscle fibers, perhaps different muscle unit types in the three muscles. Based on the morphology of medial nuclear cells and the probable actions of the muscles they innervate, we hypothesize that the medial motor nucleus may represent a discrete functional system for producing bilaterally synchronous muscle activation, and that this system is accessed by a subset of muscles in the cervical complex.
Hypothalamic and ventral thalamic projections to the superior colliculus in the cat
Authors: Rieck Richard W. , Huerta Michael F. , Harting John K. , Weber Joseph T. 
Published: January 2005

AbstractThe present report describes the organization of collicular afferents that arise within either the hypothalamus or the ventral thalamus. Following the placement of large injections of WGA‐HRP into the superior colliculus of the cat, retrogradely labeled neurons are located within the reticular nucleus of the thalamus, the zona incerta, the fields of Forel, and throughout the hypothalamus. Although the dorsal hypothalamic area contains the largest number of labeled hypothalamic neurons, labeled cells are also found within the periventricular, paraventricular, dorsomedial, ventromedial, posterior, lateral, and anterior hypothalamic nuclei. A strikingly similar pattern of distribution of labeled neurons is also observed following placement of small injections of WGA‐HRP that are restricted within the stratum griseum intermedium (SGI). In contrast, hypothalamic and ventral thalamic labeling is not seen after placement of injections within the stratum griseum superficiale. Following the placement of injections of tritiated anterograde tracers within the dorsal hypothalamic area, transported label is organized in two bands of clusters over the SGI. When injections of tritiated tracers are placed within the zona incerta, terminal label is also located over the SGI; however, the distribution of silver grains does not appear as clusters or distinct puffs. On the basis of the comparison of the cellular types that give rise to these projections and the differences in terminal distribution, we suggest that the hypothalamic and ventral thalamic projections to the superior colliculus are totally separate and unrelated pathways. The functional implications of the hypothalamotectal pathway are also discussed.
Immunocytochemical localization of luteinizing hormone‐releasing hormone (LHRH) pathways in the sheep brain during anestrus and the mid‐luteal phase of the estrous cycle
Authors: Lehman Michael N. , Robinson Jane E. , Karsch Fred J. , Silverman Ann‐Judith 
Published: January 2005

AbstractThe luteinizing hormone‐releasing hormone (LHRH) system of the sheep brain was examined by light microscopic immunocytochemistry with thick, unembedded sections. We compared the distribution and morphology of LHRH cells and their fibers in intact and ovariectomized anestrous ewes, and in breeding season ewes during the mid‐luteal phase of their estrous cycle. In all animals, a majority of LHRH neurons were found in the medial preoptic area adjacent to the organum vasculosum of the lamina terminalis. These cells formed a continuum rostrally with immunoreactive neurons in the diagonal band of Broca and medial septum and caudally with cells in the ventrolateral anterior hypothalamus and lateral hypothalamus. Relatively few cells (1–2%) were seen in the arcuate nucleus or its vicinity. Preoptic LHRH neurons project to the tubero‐infundibular sulcus of the median eminence by at least two routes: a major ventrolateral projection above the optic tract in the anterior and lateral hypothalamus, and a less prominent periventricular pathway along the third ventricle. LHRH fibers were also observed in a number of extrahypothalamic regions, including the medial amygdala and the accessory olfactory bulb.Immunoreactive LHRH neurons in the sheep exhibited a complex light microscopic morphology unlike that seen in LHRH cells of any other species to date. LHRH cells with extensive, branching processes were frequently found in clusters with close somatic appositions between neighboring cells. Multiple thin protuberances emanated from the soma of many immunoreactive neurons. Immunoreactive fibers with beaded varicosities often were intimately associated with both cell bodies and their dendritic processes. Morphometric analyses revealed that preoptic LHRH neurons in three of four mid‐luteal phase ewes had a shorter total dendritic length than those neurons in either intact or ovariectomized anestrous ewes, but this difference between breeding season and anestrous ewes was not statistically significant. Evidence for possible seasonal and/or steroid‐induced alterations in the morphology of LHRH neurons must be documented by further studies, including immunocytochemical observations at an ultrastructural level.
Laminar distribution and patchiness of cytochrome oxidase in mouse superior colliculus
Authors: Wiener Sidney I. 
Published: January 2005

AbstractThe cytochrome oxidase (CO), acetylcholinesterase (AChE), myelin, and Nissl stains were studied and compared to develop an anatomical system identifying the laminar architecture of the mouse superior colliculus. The CO and myelin stains are shown to define collicular laminae more distinctly than does the Nissl stain. The layer of large rostrocaudally coursing fiber bundles that has formerly been referred to in the rodent literature as stratum album intermediale (SAI; layer V) is renamed as a sublayer of the stratum griseum intermediale (SGI; layer IV) to conform with the nomenclature for the cat superior colliculus of Kaneseki and Sprague ('74, J. Comp. Neurol. 158:319–338).Patches of CO activity in layer IV (SGI) are shown that contain intensely stained, large, multipolar cell bodies. The CO patches do not correspond to those previously reported for AChE. The CO, myelin, and AChE stains all Indicate the presence of a large lateral extension termed the flank of layer IV (SGI). In contrast to the classical lamination pattern of the superior colliculus, the flank has no overlying layer II (stratum griseum superficiale, SGS) or layer III (stratum opticum, SO).