bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of cerebellothalamic and nigrothalamic projections in the dog: A double anterograde tracing study
Authors: Sakai Sharleen T. , Patton Kathleen 
Published: January 2005

AbstractThe distribution of nigrothalamic and cerebellothalamic projections was investigated in the dog by a double labeling strategy combining the anterograde transport of wheat germ agglutinin conjugated to horseradish peroxidase (WGA‐HRP) and tritiated amino acids. Following tritiated amino acid injections into the substantia nigra pars reticulata (SNr) and WGA‐HRP injections into the contralateral cerebellar nuclei, we found that the nigrothalamic and cerebellothalamic afferents distribute to three main targets: the central portion of the ventral anterior nucleus (VA) and the ventral lateral nucleus (VL), the internal medullary lamina (IML) region, which includes the paralaminar VA, the mediodorsal nucleus (MD) and the central lateral nucleus (CL), and finally the ventromedial nucleus (VM). We observed three distribution patterns of labeled fibers: (a) Dense single label was observed in the central portion of VA following the SNr injections and in VL following the cerebellar nuclei injections. (b) A complementary pattern consisting of alternating foci of nigral and cerebellar label was found in the IML region. This pattern was also observed in the caudal intralaminar nuclei where cerebellar label predominated in the centrum medianum (CM), while the parafascicular nucleus (Pf) primarily contained nigral label. (c) An overlapping pattern of autoradiographic and WGA‐HRP label was found in the lateral half of the VM. Overall, the distribution of nigrothalamic and cerebellothalamic projections was widespread throughout much of rostrocaudal thalamus. However, the pattern of projections varied along a continuum from lateral to medial thalamus. In lateral thalamus, nigral and cerebellar projections distributed to separate nuclei while in medial thalamus, the projection pattern changed to focal and complementary in the IML and overlapping in VM. Taken together, these thalamic projections may constitute crucial links in different functional channels involved in alerting and orienting mechanisms associated with motor behavior. Our findings also suggest that the organization of motor thalamic afferents in the dog shares similarities with the segregated and parallel circuitry characteristic of primates as well as with the overlapping and converging circuits of rodents and other carnivores.
Neuronal projections to the medial preoptic area of the sheep, with special reference to monoaminergic afferents: Immunohistochemical and retrograde tract tracing studies
Authors: Tillet Yves , Batailler Martine , Thibault Jean 
Published: January 2005

AbstractThe preoptic area contains most of the luteinizing hormone releasing hormone immunoreactive neurons and numerous monoaminergic afferents whose cell origins are unknown in sheep. Using tract tracing methods with a specific retrograde fluorescent tracer, fluorogold, we examined the cells of origin of afferents to the medial preoptic area in sheep. Among the retrogradely labeled neurons, immunohistochemistry for tyrosine hydroxylase, dopamine‐β‐hydroxylase, phenylethanolamine N‐methyltransferase, and serotonin was used to characterize catecholamine and serotonin fluorogold labeled neurons.Most of the afferents came from the ipsilateral side to the injection site. It was observed that the medial preoptic area received major inputs from the diagonal band of Broca, the lateral septum, the thalamic paraventricular nucleus, the lateral hypothalamus, the area dorsolateral to the third ventricle, the perimamillary area, the amygdala, and the ventral part of the hippocampus. Other numerous, scattered, retrogradely labeled neurons were observed in the ventral part of the preoptic area, the vascular organ of the lamina terminalis, the ventromedial part of the hypothalamus, the periventricular area, the area lateral to the interpeduncular nucleus, and the dorsal vagal complex. Noradrenergic afferents came from the complex of the locus coeruleus (A6/A7 groups) and from the ventro‐lateral medulla (group A1). However, dopaminergic and adrenergic neuronal groups retrogradely labeled with fluorogold were not observed. Serotoninergic fluorogold labeled neurons belonged to the medial raphe nucleus (B8, B5) and to the serotoninergic group situated lateral to the interpeduncular nucleus (S4).In the light of these anatomical data we hypothesize that these afferents have a role in the regulation of several functions of the preoptic area, particularly those related to reproduction. Accordingly these afferents could be involved in the control of luteinizing hormone releasing hormone (LHRH) pulsatility or of preovulatory LHRH surge.
Intrinsic GABAergic neurons in the rat central extended amygdala
Authors: Sun Ning , Cassell Martin D. 
Published: January 2005

AbstractThe present study examined the distribution, morphology, and connections of gamma‐aminobutyric acid‐immunoreactive (GABA‐IR) neuros in the three principal components of the central extended amygdala: the central amygdaloid nucleus, the bed nucleus of the stria terminalis (BNST) and the sublenticular substantia innominata. In the central nucleus, large numbers of GABA‐IR neurons were identified in the lateral, lateral capsular, and ventral subdivisions, though in the medial subdivision, GABA‐IR neurons were only present at very caudal levels. Combined immunocytochemistry‐Golgi impregnation revealed that GABA‐IR neurons in the lateral central nucleus were medium‐sized spiny neurons that were morphologically similar to GABAergic neurons in the striatum. Injections of horseradish peroxidase into the bed nucleus of the stria terminalis labeled a major proportion of the GABA‐IR neurons in the central nucleus. In the bed nucleus, the majority of GABA‐IR neurons were located in the anterolateral subdivision, ventral part of the posterolateral subdivision and the parastrial subdivision. GABA‐IR neurons in the anterolateral bed nucleus were of the typical mediumsized spiny type. Injections of horseradish peroxidase into the central nucleus labeled a few GABA‐IR neurons in the posterior part of the anterolateral bed nucleus. GABA‐IR neurons were identified in the sublenticular substantia innominata and medial shell of the nucleus accumbens and contributed to the continuum of GABA‐IR extending from the central nucleus to the bed nucleus. Injections of horseradish peroxidase (HRP) into the central nucleus, but not the BNST, labeled a few GABA‐IR neurons in the substantia innominata. The data point to GABA‐IR neurons being a characteristic feature of the central extended amygdala and that GABA‐IR neurons participate in the long intrinsic connections linking the major components of this structure. Since lesions of the stria terminalis and basolateral amygdaloid nucleus failed to deplete GABA‐IR terminals in the central nucleus, the role of GABA in local and short intrinsic connections in the central extended amygdala is discussed. Further, physiological findings implicating the intrinsic GABAergic system of the central extended amygdala in the tonic inhibition of brainstem efferents are reviewed.
Reorganization of the chick basilar papilla after acoustic trauma
Authors: Raphael Yehoash 
Published: January 2005

AbstractThe auditory epithelium in birds and mammals consists of a postmitotic population of hair cells and supporting cells. Unlike mammals, birds can regenerate their auditory epithelia after trauma. Recent evidence indicates that supporting cells undergo mitosis after acoustic trauma, suggesting that supporting cells may transdifferentiate into hair cells. The goals of this study were to (1) characterize the responses of hair cells and supporting cells to acoustic trauma, and (2) determine whether hair cell loss is a prerequisite for generation of new hair cells. Chicks were exposed to an octave‐band noise and their inner ears assayed with fluorescence or scanning electron microscopy. In one area of the basilar papilla, defined as the center of the lesion, extensive hair cell degeneration occurred. Expanded supporting cells obliterated degenerating hair cells and invaded spaces normally occupied by hair cells. Aggregates of DNA were found within the basilar papilla, suggesting that hair cell death and disintegration may occur within the epithelium. The epithelial sheet appeared structurally confluent at all times examined. Supporting cells exhibited altered apical contour in distal regions of the basilar papilla, where hair cell damage was mild or inconspicuous. Four days after noise exposure, newly generated hair cells were found in the center of the lesion and in the distal areas, where no hair cell loss could be detected. The results suggest that supporting cells may play an important role in maintenance and repair of the traumatized basilar papilla and raise the possibility that production of new hair cells is not dependent on hair cell loss in the immediate vicinity.
The fate of cryopreserved nerve isografts and allografts in normal and immunosuppressed rats
Authors: Zalewski Andrew A. , Fahy Gregory M. , Azzam Nabil A. , Azzam Rita N. 
Published: January 2005

AbstractDonor Schwann cells, perineurial cells, and vasculature are known to survive in grafts of peripheral nerve. In the present study, we attempted to cryopreserve nerve to determine whether these cellular components of nerve would survive after transplantation and support host axonal regeneration through the graft. Four‐centimeter lengths of peroneal nerves were removed from inbred adult American Cancer Institute (ACI) rats and placed into vials that contained a cryoprotective mixture of dimethyl sulfoxide and formamide (DF) at room temperature. Each vial with nerves in DF was cooled at a rate of 1–1.5°C/minute down to –40°C at which point the vials were plunged into liquid nitrogen at –196°C. After 5 weeks of storage, the nerves were thawed and DF removed. Some of the cryopreserved‐thawed ACI nerves were transplanted as isografts into the legs of ACI rats. Other ACI nerves were used as allografts and inserted into immunologically normal Fischer (FR) rats that were untreated or were immunosuppressed with the drug Cyclosporin A (Cy‐A). At surgery, only one end of the nerve graft was joined to the cut proximal end of the peroneal nerve of the host. The cellular elements of ACI grafts were present at 5 weeks in grafts removed from ACI rats and FR rats treated with Cy‐A. Non‐immunosuppressed FR rats rejected ACI nerves as did FR rats in whom Cy‐A was stopped after 5 weeks of treatment. All surviving ACI grafts underwent Wallerian degeneration and consisted of columns of Schwann cells, which in their proximal portion were associated with regenerating host axons. The donor perineurial sheath and vasculature were also present in surviving grafts. ACI isografts only were examined 20 weeks postoperatively. All normal tissue components survived in these older grafts and contained regenerated and myelinated host axons throughout their 4 cm lengths. These results demonstrated that the cellular elements of nerve can be cryopreserved, and after transplantation, survive and function. Because nerves survived after prolonged cryopreservation, it seems feasible to establish a nerve bank from which grafts can be withdrawn to repair gaps in injured nerves. However, cryopreserved nerves used as allografts remain immunogenic and require immunosuppression for their survival. Published in 1993 by Wiley‐Liss, Inc.
Pigment‐dispersing hormone‐like peptide in the nervous system of the flies Phormia and Drosophila: Immunocytochemistry and partial characterization
Authors: Nässel Dick R. , Shiga Sakiko , Mohrherr Carl J. , Rao K. Ranga 
Published: January 2005

Abstractβ‐pigment‐dispersing hormone (β‐PDH) isolated from the fiddler crab (Rao et al., '85) is a member of an octadecapeptide family of neuropeptides common to arthropods. Whereas earlier studies of these peptides in insects were limited to orthopterans, this investigation focuses on dipteran flies. Extracts of heads from the blowfly Phormia terraenovae were assessed in a fiddler crab bioassay for PDH activity. Immunocytochemistry, dose‐response curves, gel filtration chromatography and reversed‐phase HPLC, combined with bioassay and enzymelinked immunosorbent assay (ELISA), indicate the presence of PDH‐like peptide in the blowfly. Immunocytochemical mapping of PDH‐like immunoreactive (PDHLI) neuroans was performed for the entire nervous systems of Phormia and the fruitfly Drosophila with a β‐PDH antiserum. In the cephalic ganglion (brain, optic lobe and subesophageal ganglion) PDHLI cell bodies could be detected (34 in Phormia and 16 in Drosophila). In both species, each hemisphere contains 8 PDHLI cell bodies in the optic lobes. These innervate the optic lobe neuropils bilaterally. In Phormia, another set of 8 cell bodies are located in each of the lateral neurosecretory cell groups in the superior protocerebrum. These neurons send axons to the corpora cardiaca‐hypocerebral ganglion complex and to portions of the foregut. In contrast, only the optic lobe neurons display immunoreactivity in Drosophila. Except for the optic lobes, PDHLI processes are distributed only in nonglomerular neuropils of the brain of both species. In the fused thoracico‐abdominal ganglia of Phormia, 28 PDHLI cell bodies were found (only six were found in Drosophila). In both species, six abdominal PDHLI neurons are efferents with axons innervating the hindgut. We also found that some of the PDHLI neurons in the Phormia brain and abdominal ganglion contain colocalized FMRFamide‐like immunoreactivity. Since the flies studied here do not display hormonally controlled, fast pigment migrations, the PDH‐like peptide may have a role as neurotransmitter or neuromodulator in the central nervous system, especially in the visual system, and a regulatory role in the stomatogastric system and the hindgut. © 1993 Wiley‐Liss, Inc.
Projections of physiologically characterized spherical bushy cell axons from the cochlear nucleus of the cat: Evidence for delay lines to the medial superior olive
Authors: Smith Philip H. , Joris Philip X. , Yin Tom C. T. 
Published: January 2005

AbstractBushy cells in the anteroventral cochlear nucleus (AVCN) receive their principal excitatory input from the auditory nerve and are the primary source of excitatory input to more centrally located brainstem auditory nuclei. Despite this pivotal position in the auditory pathway, details of the basic physiological information being carried by axons of these cells and their projections to more central auditory nuclei have not been fully explored.In an attempt to clarify these details, we have physiologically characterized and anatomically labeled individual axons of the spherical bushy cell (SBC) class of the cat AVCN. The characteristic frequencies (CFs) of our injected SBC population are low, all less than 12 kHz and primarily (83%) less than 3 kHz, while their spontaneous activity is comparatively high (mean of 59 spikes/sec). In response to short tone bursts at CF, low CF (< 1 kHz) SBC units can phase‐lock better than auditory nerve fibers. SBCs with CFs above 1 kHz have primary‐like responses at all stimulus levels and can show robust phase‐locking to an off‐CF, 500 Hz tone. When compared with our previously reported population of labeled globular bushy cells (GBC; Smith et al., 1991, J. Comp. Neurol. 304:387–407), some similarities and differences are apparent in both physiological response properties and axonal projection pattern. GBCs show no low frequency bias in CFs, have lower spontaneous rates, and the high CF units exhibit a primary‐like‐with‐notch response at high stimulus levels as a consequence of a very well timed onset component. Low CF, GBC short tone responses are indistinguishable from those of SBCs. Anatomically, the axons of SBCs cross the midline in the dorsal component of the trapezoid body and typically innervate the medial superior olive (MSO) on both sides, the ipsilateral lateral superior olive (LSO), and the contralateral ventral nucleus of the lateral lemniscus (VNLL). The projections to the contralateral, but not the ipsilateral MSO, show a rostral to caudal delay line configuration, similar to the scheme first proposed by Jeffress (1948, J. Comp. Neurol. 41:35–39). The form of this delay line is consistent with the topographic map of interaural time delays reported by Yin and Chan (1990, J. Comp. Neurol. 64:465–488.). Projections to the ipsilateral LSO often take an indirect route. In contrast, GBC axons travel in the ventral component of the trapezoid body, never innervate the MSO, rarely innervate the ipsilateral LSO, and always innervate the contralateral medial nucleus of the trapezoid body. The terminal specializations of both SBC and GBC axons contain round vesicles. © 1993 Wiley‐Liss, Inc.
Midbrain dopaminergic neurons (nuclei A8, A9, and A10): Three‐dimensional reconstruction in the rat
Authors: German Dwight C. , Manaye Kebreten F. 
Published: January 2005

AbstractThe dopaminergic neurons in the midbrain of the rat are located in three cell groups: nucleus A8 cells in the retrourbal field, nucleus A9 cells in the substantia nigra, and nucleus A10 cells in the ventral tegmental area and related nuclei. The purpose of the present study was to map and quantify the midbrain dopaminergic neurons in two and three dimensions in the rat brain, using immunohistochemical staining and computer imaging techniques. The cells were identified with an antibody against tyrosine hydroxylase, and counted in six midbrain nuclei: the retrorubral field, substantia nigra pars compacta, substantia nigra pars reticulata, central linear nucleus, ventral tegmental area, and interfascicular nucleus. Outlines were traced around the perimeters of the coronal tissue sections, and the locations of all immunoreactive ventral midbrain cells were mapped. On one side of the brain there are approximately 1,300 nucleus A8 cells, 10,500 nucleus A9 cells, and 10,200 nucleus A10 cells. The 2‐ and 3‐dimensional reconstructions illustrate the region‐specific density of dopaminergic neurons throughout the midbrain cell complex, and provide a visual appreciation of the location and distribution of the three dopaminergic cell groups in relation to their position in the midbrain. Information about the number and location of midbrain dopaminergic neurons will be useful in conjunction with future studies that characterize these cells more specifically, for example, in terms of their co‐transmitters, and afferent and efferent projections. © 1993 Wiley‐Liss, Inc.
Medial cortex of the lizard Gekko gecko: A hodological study with emphasis on regional specialization
Authors: Hoogland Piet V. , Vermeulen‐Vanderzee Eefke 
Published: January 2005

AbstractThere is increasing evidence that the archicortex in mammals and reptiles is not a homogeneous structure. However, little is known about the regional specialization of this cortical area in reptiles. Therefore, the efferent connections of the medial cortex of the lizard Gekko gecko were studied with the anterograde tracer Phaseolus vulgaris‐leucoagglutinin. The small‐celled part of the medial cortex (Cxms) projects to various parts of the septum in a topological way: the rostral part projects to the anterior septal nucleus, whereas the caudal part projects to the lateral septal nucleus and the nucleus septi impar. In addition, Cxms projects to the large‐celled part of the medial cortex (Cxml). Axons that originate from the dorsal part of Cxms terminate at the proximal parts of the apical and basal dendrites of the neurons of Cxml caudal to the injection site. In contrast, fibers originating from the ventral part terminate on more distal parts of the dendrites of neurons of Cxml rostral to the injection site. Other projections from Cxms to the dorsal cortex (Cxd) and the external amygdaloid nucleus were found.The Cxml projects bilaterally to Cxms. These projections terminate in the superficial and deep plexiform layers. In addition, projections to the cell plate of Unger, Cxd, and to the lateral septal nucleus were found.It appears, on the basis of the efferent connections, that Cxms can be divided into a rostral and caudal part, while hodological differences also exist between the dorsal and ventral parts of Cxms. The results of the present study do not suggest a subdivision of Cxml. The regional variations of the medial cortex in the lizard Gekko gecko differ from the regional variations described in other reptilian species. © 1993 Wiley‐Liss, Inc.
Noradrenaline in the brain of the south african clawed frog Xenopus laevis: A study with antibodies against noradrenaline and dopamine‐β‐hydroxylase
Authors: González Agustín , Smeets Wilhelmus J. A. J. 
Published: January 2005

AbstractTo obtain insight into the noradrenergic system of amphibians, the distribution of noradrenaline was studied immunohistochemically with antibodies against noradrenaline (NA) and dopamine‐β‐hydroxylase (DBH) in the brain of the South African clawed frog Xenopus laevis. Noradrenaline‐containing cell bodies are found in the hypothalamic periventricular organ, the isthmic region, and in an area ventral and medial to the solitary tract. Noradrenaline‐immunoreactive (NAi) fibers are widely, but not uniformly, distributed throughout the brain and spinal cord. In the telencephalon, dense plexuses of NAi fibers are present dorsomedial to the nucleus accumbens, in the nucleus of the diagonal band, the dorsolateral part of the striatum, the medial amygdala, and in an area that encompasses the lateral forebrain bundle. In the diencephalon, dense plexuses are found ventrolateral to the periventricular organ, in the posterior tubercle, and in the intermediate lobe of the hypophysis. Compared to the forebrain, the brainstem and spinal cord are less densely innervated by NAi fibers.The distribution of DBHi cell bodies and fibers resembles the pattern revealed with the NA antibodies. An exception is formed by the liquor contacting cells of the hypothalamic periventricular organ, which are immunonegative for the DBH antiserum. It is suggested that these cells accumulate rather than metabolize catecholamines. The present study, combined with the results of a previous report in Xenopus on the distribution of dopamine (González, Tuinhof, Smeets, '93, Anat. Embryol. 187:193–201) offers the opportunity to differentiate between the two catecholamines. For example, it is now shown that both dopaminergic and noradrenergic fibers innervate the intermediate lobe of the hypophysis and that, therefore, both catecholamines are likely involved in background adaptation. © 1993 Wiley‐Liss, Inc.