bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of corticotropin‐releasing factor in the cerebellum and precerbellar nuclei of the opossum: A study utilizing immunohistochemistry, In situ hybridization histochemistry, and receptor autoradiography
Authors: Cummings Sharon L. , Young W. Scott , Bishop Georgia A. , King James S. , De Souza Errol B. 
Published: January 2005

AbstractThis study reports (1) a nonhomogeneous distribution of three morphologically distinct, corticotropin‐releasing factor (CRF)‐immunoreactive axonal phenotypes within the cerebellum of the opossum: climbing fibers, mossy fibers, and beaded fibers within the ganglionic plexus; (2) the existence of CRF binding sites within the cerebellar cortex; and (3) the distribution of CRF‐containing neurons in brainstem precerebellar nuclei identified with immunohistochemistry and in situ hybridization histochemistry. CRF‐immunoreactive climbing and/or mossy fibers were identified within all cerebellar lobules. The density of CRF‐immunoreactive fibers was greatest in the vermis, where longitudinal bands of intensely immunoreactive climbing and mossy fibers were interspersed with regions containing fibers demonstrating lower levels of immunolabeling. CRF‐immunoreactive fibers were present within all deep cerebellar nuclei. The topography of CRF‐containing cerebellar fibers is discussed with respect to possible sites of origin within the brainstem. CRF‐immunoreactive neurons were identified in all nuclei of the inferior olivary complex, although the number and intensity of immunostaining of CRF‐containing cells varied within and among individual nuclei. CRF‐immunoreactive somata were also present in brainstem nuclei known to give rise to cerebellar mossy fibers. In situ hybridization histochemistry utilizing an 35S‐labeled synthetic 48‐base oligodeoxynucleotide complementary to amino acids 22–37 of rat CRF proper revealed that CRF mRNA is transcribed in precerebellar nuclei. Variation in the level of CRF mRNA was detected among inferior olivary nuclei, in correspondence with variations detected in the levels of immunostaining. Data from this study suggest that variation in the level of CRF immunoreactivity detected within cerebellar afferent fibers may correlate with the level of CRF mRNA within cell bodies of origin of the projections. In vitro receptor autoradiography, utilizing 125I‐Tyro‐ovine CRF, revealed correspondence between CRF binding sites and CRF‐immunoreactive fibers in the cerebellar cortex. Results of this study support suggestions for CRF‐mediated circuitry in the cerebellum.
Localization of vasoactive intestinal peptide‐ and peptide histidine isoleucine amide‐like immunoreactivities in the rat superior cervical ganglion and its nerve trunks
Authors: Sasek Cathrine A. , Zigmond Richard E. 
Published: January 2005

AbstractElectrical stimulation of the preganglionic cervical sympathetic trunk causes an increase in dopa synthesis in the postganglionic neurons in the superior cervical ganglion (SCG). This transsynaptic biochemical effect can be blocked only partially by cholinergic antagonists, suggesting the involvement of a noncholinergic preganglionic sympathetic neurotransmitter(s). A survey of a large number of possible candidates for this neurotransmitter revealed that, in addition to cholinergic agonists, only a small group of peptides (all members of the secretin‐glucagon family) stimulated dopa synthesis in the SCG. The effective peptides included vasoactive intestinal peptide (VIP), peptide histidine isoleucine amide (PHI), and secretin. Consequently we looked for the presence of immunoreactivities for these three peptides in the SCG.VIP‐ and PHI‐like immunoreactive fibers were found in the SCG and in its major pre‐ and postganglionic nerve trunks. The distributions of the two immunoreactivities were very similar. Immunoreactive fibers were seen both singly and in bundles. In some instances, fibers were found apposed to neuronal cell bodies in the ganglion, and occasionally dense plexuses of fibers were found surrounding the neurons. In addition, punctate immunoreactive profiles were found apposed to the neurons in what appeared to be terminal fields. A small number of immunoreactive neuronal cell bodies were also seen in the ganglion. In a few instances, it was possible to establish, in serial sections, that the same cell body was immunostained with both VIP and PHI antisera. No secretin like‐immunoreactive fibers or cells were observed. The presence of VIP‐like and PHI‐like‐immunoreactive fibers in the cervical sympathetic trunk and in the SCG strengthens the possibility that these peptides, or a related molecule(s), serve as preganglionic neurotransmitters in this ganglion.
Ultrastructural analysis of dynorphin B–immunoreactive cells and terminals in the superficial dorsal horn of the deafferented spinal cord of the rat
Authors: Cho Hee Jung , Basbaum Allan I. 
Published: January 2005

AbstractLight microscopic studies have demonstrated important differences in the distribution of enkephalin and dynorphin cells and terminals in the dorsal horn. Most importantly, dynorphin neurons are located in regions almost exclusively associated with the transmission and/or control of nociceptive messages (laminae I, IIo, and V); enkephalin neurons, although located in the same regions, are also found in areas involved in the transmission of nonnociceptive messages, e.g., laminae IIi and III. To determine whether there are also differences in the synaptic organization of the two opioid peptides, we have examined the distribution of dynorphin B immunoreactivity at the ultrastructural level. The studies were performed in colchicine‐treated rats that underwent dorsal rhizotomy so that the relationship of dynorphin terminals and cells to primary afferent terminals could be established.Dynorphin B–immunoreactive cell bodies and dendrites in laminae I and IIo receive convergent primary and nonprimary afferent input, which suggests that dynorphin neurons receive a small‐diameter, nociceptive input. Dynorphin terminals predominantly contain round, agranular vesicles; some terminals also contain a few dense core vesicles. Most dynorphin terminals are presynaptic to unlabelled dendrites; both asymmetric and symmetrical axonal contacts were noted. Dynorphin‐immunoreactive boutons are also presynaptic to unlabelled cell bodies and spines. Twenty‐nine percent of dynorphin terminals were associated with axonal profiles, including degenerating primary afferent terminals; only rarely could a synaptic density be detected. Although some degenerating primary afferent terminals were clearly presynaptic to dynorphin‐immunoreactive terminals, in most cases, the polarity of the relationship between primary afferents and dynorphin terminals could not be established.These data indicate that synaptic interactions made by and with dynorphin‐immunoreactive cells and terminals in the superficial dorsal horn are not very different from those that were previously reported for enkephalin cells and terminals. Thus, it is unlikely that dynorphin terminals provide a significant presynaptic input to primary afferent fibers. On the other hand, the presence of a primary afferent input to dynorphin cell bodies and dendrites in the superficial dorsal horn suggests that dynorphin cells receive a direct input from small‐diameter, nociceptive primary afferents. That connection might contribute to the increased levels of dynorphin message and peptide that have been reported in rats experiencing a chronic inflammatory condition. The possibility that dynorphin neurons are associated more with the transmission than the control of nociceptive messages is discussed.
Further evidence for excitatory amino acid transmission in lamprey reticulospinal neurons: Selective retrograde labeling with (3H)D‐aspartate
Authors: Brodin Lennart , Ohta Yoshihiro , Hölkfelt Tomas , Grillner Sten 
Published: January 2005

AbstractThe distribution of radiolabeled neurons in the brain stem of Lampetra fluviatilis was studied following unilateral injections of (3H)D‐aspartate in the rostral spinal cord. After survival periods of 1–3 days, labeled perikarya were present within and nearby the posterior, middle, and anterior rhombencephalic reticular nuclei and in the mesencephalic reticular nucleus. The highest number of (3H)D‐aspartate labeled cell bodies were present in the posterior rhombencephalic reticular nucleus. The labeled reticulospinal neurons were distributed mainly ipsilateral to the injection site and included the giant Müller cells as well as medium‐sized and small neurons. Contralateral labeling occurred in cell bodies scattered along the lateral margin of the rhombencephalic reticular formation, the most rostral of these contralaterally projecting neurons being the Mauthner cell. The (3H)D‐aspartate labeling correlates with previous electrophysiological studies showing that lamprey reticulospinal neurons utilize excitatory amino acid transmission.
Gap junction protein in rat hippocampus: Light microscope immunohistochemical localization
Authors: Yamamoto T. , Shiosaka S. , Whittaker M. E. , Hertzberg E. L. , Nagy J. I. 
Published: January 2005

AbstractAn affinity‐purified antibody against a 27‐kD rat liver gap‐junctional protein (GJP) was used to determine the distribution of GJP immunoreactivity in section of rat hippocampus. Four heterogeneously distributed GJP‐immunostaining patterns were observed. The two most common were punctate immunoreactive elements ranging in size from 0.3 to 0.7 μm and networks of immunoreactive varicose fibers coursing in a variety of directions within the various hippocampal layers and ranging in length from a few microns up to 200 μm. The density of punctate immunostaining was highest within a portion of the stratum pyramidale, at the border between the stratum pyramidale and stratum oriens, and at the border between the molecular and granule cell layers of the dentate gyrus. Moderate to low densities were observed in other hippocampal areas. Immunoreactive fibers were most concentrated within the border portions of the stratum pyramidale and oriens, moderately distributed in the stratum radiatum and the remaining part of the stratum oriens, and sparse in the alveus. In the dentate gyrus, fiber networks were most evident at the border between the granule cell and molecular layers and very unevenly distributed in the molecular layer. The two other patterns observed included intense filamentous immunostaining within a small number of neuronal perikarya located mainly in the stratum pyramidale of areas CA2 and CA3, but rarely in area CA1 or the dentate gyrus, and diffuse immunostaining of small cell bodies dispersed throughout the hippocampus but most numerous in the vicinity of the stratum pyramidale and in the alveus. All of these immunostaining patterns were seen at all rostrocaudal hippocampal levels. These results suggest that if GJP‐immunoreactive fibers and neurons observed in the hippocampus have the capacity to form gap junctions, then electrotonic transmission may constitute an important means of information processing within this structure.
Spinocerebellar projections from the upper lumbar segments in the cat, as studied by anterograde transport of wheat germ agglutinin‐horseradish peroxidase
Authors: Yaginuma Hiroyuki , Matsushita Matsuo 
Published: January 2005

AbstractThe projection fields of the dorsal spinocerebellar tract (DSCT) arising from Clarke's column, marginal neurons of Clarke's column, and lamina V neurons in the upper lumbar segments were studied by the anterograde transport of wheat germ agglutinin conjugated to horseradish peroxidase (WGA‐HRP) in the cat. To label only these neuron groups with uncrossed ascending axons, the spinal cord was lesioned rostral and contralateral to the WGA‐HRP injections.Following injections of WGA‐HRP into the L1‐L4 segments, labeled terminals were seen in sublobules Ia‐VIc and VIIb‐VIIIb, the simple lobule, the paramedian lobule, and the dorsal paraflocculus. About 70–80% and 20–30% of the total number of labeled terminals were in the anterior and the posterior lobe, respectively; the projections were predominantly ipsilateral to the cells of origin (about 87% or more labeled terminals of the total number in each of sublobules IIb‐Va). The labeled terminals were abundant in sublobule IIb (6–11%), lobule III (12–27%), and sublobules IVa (14–17%) and IVb (14–21%). In the mediolateral extent of the lobules in the anterior lobe, the labeled terminals were most numerous between 1.1 and 3.0 mm lateral to the midline (45–75% of the total number of labeled terminals on the ipsilateral side). In the posterior lobe labeled terminals were numerous in sublobule VIIIb (13.6%) and sublobule C of the paramedian lobule (15–19%).The projection fields in the horizontal plane of the lobules were reconstructed from a series of cross sections through each lobule. In the anterior lobe the labeled terminals were distributed in eight major areas. In sublobules IIb‐III, areas 1–3 were located within 1.0 mm of the midline in zone A of Voogd; areas 4–6, between 1.0 and 2.5 mm lateral to the midline in zones B‐C1; and areas 7 and 8, lateral to 3.0 mm from the midline in zones C2 and C3. Areas 1–6 extended apicobasally in the middle part of the lobules. In sublobule VIIIb projections were confined to three longitudinal areas whereas in the paramedian lobule the projection areas were less distinct.The projection pattern of the lumbar DSCT was different from that of the thoracic DSCT reported previously. In the anterior lobe the thoracic DSCT projects to five areas in the medial (zone A) and the lateral part (zone B) of the vermis and to four areas in the intermediate region of the hemisphere (zones C1‐C3).
Localization of atrial natriuretic factor (ANF) binding sites in the central nervous system of the frog
Authors: Tong Yiai , Netchitaïlo Pierre , Leboulenger Françlois , Vaudry Hubert , Pelletier Georges 
Published: January 2005

AbstractThe distribution of atrial natriuretic factor (ANF) binding sites was investigated in the central nervous system of the frog Rana ridibunda using the technique of in vitro receptor autoradiography by means of [125I]‐labeled ANF‐28. The anatomic distribution of ANF recognition sites was determined on Kodak ARX films apposed onto tissue sections, and their distribution was examined in greater detail by analysis of autoradiograms generated by using emulsion‐coated sections. The highest levels of ANF binding sites were found in the olfactory bulb, the dorsal pallium, the septum, the habenular nucleus, the dorsal infundibular nucleus, the interpeduncular nucleus, and in the tectum. Moderate levels of ANF binding sites were observed in the thalamus and throughout the mesencephalon, whereas low levels were detected in the lateral and medial pallium, the medial forebrain bundle, and the nucleus rotondus. In the pituitary gland, the neural and distal lobes were densely loaded with ANF binding sites, whereas no autoradiographic labeling was observed in the pars intermedia. In general, there was a good correlation between the location of ANF receptors and the distribution of ANF‐containing neurons, as previously determined by immunocytochemistry. Together these results support the view that ANF may act as a neurotransmitter or a neuromodulator in various regions of the frog brain.
Serotoninergic neurons in the retina of Xenopus laevis: Selective staining, identification, development, and content
Authors: Frederick Jeanne M. , Rayborn Mary E. , Hollyfield Joe G. 
Published: January 2005

AbstractUptake of 3H‐serotonin followed by autoradiography, and uptake of the serotonin analog 5,7‐dihydroxytryptamine (5,7‐DHT), with subsequent staining, were each used to define a unique set of neurons in the retina of the African clawed frog, Xenopus laevis. Both techniques demonstrated the same population of neurons, on the basis of perikaryal size, shape, and position within the retina. Two classes of amacrine cells accumulated 5,7‐DHT at the proximal (vitread) margin of the inner nuclear layer; the two classes were distinguished by the size of their perikarya. Two similar populations of cells, observed in the ganglion cell layer with lower frequency, may represent “displaced” counterparts of these two amacrine cell types. A class of bipolar cells whose perikarya were located in middle‐to‐distal regions of the inner nuclear layer also accumulated 5,7‐DHT and 3H‐serotonin. Processes of these cells contributed to a dense plexus of fine fibers that appeared evenly distributed throughout the inner plexiform layer. 3H‐Serotonin‐accumulating cells first appeared in the developing retina at stage 35/36, a time immediately after retinal stratification but before elaboration of either plexiform layer. Electron microscopic analysis permitted an identification of 3H‐serotonin‐accumulating terminals in the inner plexiform layer. Serotonin‐labeled terminals containing conventional contacts, suggestive of amacrine cells, were presynaptic to unidentified processes and postsynaptic to bipolar cells. Labeled terminals containing ribbon contacts, indicative of bipolar cells, were postsynaptic to amacrine cells. The amount of serotonin contained in isolated retinas was 15 pmol/mg protein as measured by HPLC with electrochemical detection. We attempted to stimulate the release of accumulated 3H‐serotonin from mature retinas by increasing the K+‐concentration in the bathing medium. Although preloaded glycine is readily released from 14C‐glycine‐accumulating neurons, from the same retinas there was no calcium‐dependent, K+‐stimulated release of 3H‐serotonin. This finding suggests that serotonin and glycine are processed differently by retinal neurons, the consequence of which results in differing responses to 40 mM K+.
Gustatory innervation in the rabbit: Central distribution of sensory and motor components of the chorda tympani, glossopharyngeal, and superior laryngeal nerves
Authors: Hanamori Takamitsu , Smith David V. 
Published: January 2005

AbstractAlthough rabbits have been used extensively in neurophysiological studies of the gustatory system, there is little information about the anatomical organization of taste in this species. Afferent and efferent central connections of three nerves innervating oral or laryngeal taste buds in the rabbit, including the chorda tympani (CT), the lingual‐tonsillar branch of the glossopharyngeal (IX), and the superior laryngeal nerve (SLN), were traced by means of horseradish peroxidase neurohistochemistry. After entering the brainstem, most afferent fibers of CT, IX, and SLN turned caudally in the solitary tract, with fibers of the CT terminating in the nucleus of the solitary tract from 1.0 mm rostral to 3.8 mm caudal to the caudal border of the dorsal cochlear nucleus. There was terminal label from the CT also in the principal trigeminal nucleus. Preganglionic parasympathetic cell bodies of the superior salivatory nucleus were labeled retrogradely in the reticular formation ventral to the rostral pole of the solitary nucleus. Afferent fibers of the IXth nerve terminated in the solitary nucleus from 0.6 mm rostral to 5.0 mm caudal to the caudal border of the dorsal cochlear nucleus. There were also labeled terminals in the principal trigeminal nucleus and in all three divisions of the spinal trigeminal nucleus. Cell bodies composing the inferior salivatory nucleus were labeled in and around the solitary nucleus and subadjacent reticular formation just rostral to the caudal border of the dorsal cochlear nucleus. There were also a few lightly labeled cells within the nucleus ambiguus at its most rostral extent. Afferent fibers of the SLN terminated in the solitary nucleus from 1.2 to 6.8 mm caudal to the dorsal cochlear nucleus. There was also some terminal label in the intermediate and caudal divisions of the spinal trigeminal nucleus. Many cells were retrogradely labeled in the nucleus ambiguus following application of HRP to the SLN and a few cells were labeled in and around the solitary nucleus just caudal to the dorsal cochlear nucleus. These three nerves show an overlapping rostral to caudal distribution of afferent input within the nucleus of the solitary tract that may be related to their gustatory and visceral functions.
Brainstem projections to the rat cuneate nucleus
Authors: Weinberg Richard J. , Rustioni Aldo 
Published: January 2005

AbstractNeurons in the pontomedullary tegmentum have been proposed as a final common pathway subserving descending inhibition in the dorsal column nuclei. To investigate the anatomical substrate for these descending effects, brainstem projections to the cuneate nucleus of rats were studied with injections of lectin‐conjugated horseradish peroxidase. In rats with iontophoretic tracer injections in this nucleus, many labeled neurons were detected near the injection site, especially ventral and caudal to it. Intrinsic reciprocal projections were observed after injections in caudal, middle, or rostral levels of the cuneate nucleus. Neurons were labeled in the red nucleus, in agreement with previous anatomical studies, and also in the trigeminal, vestibular, and cochlear nuclei. An ipsilateral dorsomedial group of neurons was labeled in the upper cervical segments and scattered neurons were also labeled bilaterally near the central canal. Sparse retrograde labeling in the tegmetum was focused in the lateral paragigantocellular nucleus and caudal raphe. Consistent with the retrograde experiments, anterograde labeling after pressure injections of lectin‐conjugated horseradish peroxidase in the pontomedullary tegmentum was very sparse within the dorsal column nuclei; labeling was dense, however, in the region immediately ventral to these nuclei.These results confirm previous work indicating that the activity of cuneate neurons is modulated by brainstem sensory nuclei. However, it appears that direct projections to the cuneate nucleus from pontine and rostral medullary regions are sparser than previously suggested. The last link of a polysynaptic descending inhibitory pathway may include GABAergic neurons immediately adjacent to the dorsal column nuclei and/or intrinsic to these nuclei.