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Biomedical subjects

G Ju

Publications and source records attributed to G Ju.

At least 109 records · Page 6Linked to original sources
PubMed1991

Fos expression in GHB-induced generalized absence epilepsy in the thalamus of the rat.

Using the model of gamma-hydroxybutyrate (GHB)-induced generalized absence epilepsy, the present work investigated the distribution of fos oncoprotein expression in the rat thalamus with fos antibody immunohistochemistry. Thirty minutes after absence-like seizures, some fos-immunoreactive cell nuclei were found in bilateral thalamic paraventricular nuclei (PV). After a further 30 min, a massive bilateral induction of fos was observed in the lateral habenular nucleus (LHb), the PV, the rhomboid thalamic nucleus, and the intralaminar nuclei of the thalamus. These results suggest that the LHb and the midline and intralaminar thalamic nuclei may very likely be involved in the pathophysiology of absence seizures.

Animals↗
PubMed1991

Peptidergic innervation of the pars distalis of the adenohypophysis.

Substance P-like immunoreactive nerve fibers have been found in the pars distalis of the adenohypophysis in the monkey, dog, and rat. Calcitonin gene-related peptide-like immunoreactive nerve fibers have also been identified in the dog and rat. The peptidergic fibers are closely related to the glandular cells with synaptic contacts demonstrated between them. It is suggested that neural factors may be directly involved in the regulation of the activities of the anterior pituitary.

Animals↗
PubMed1991

[Responses of neurons in lateral parabrachial nucleus to antidromic stimulation of subfornical organ and to orthodromic stimulation of nucleus tractus solitarius in the rat].

Single unit discharges were extracellularly recorded from the neurons in the lateral parabrachial nucleus (LPBN) and responses of the recorded units to antidromic stimulation of the subfornical organ (SFO) and to orthodromic stimulation of the nucleus tractus solitarius (NTS) were observed in urethane-anesthetized rats. Following electrical stimulation of the SFO, 9.9% (51/151) of the LPBN units were antidromically activated. After activation of peripheral baroreceptors by raising arterial blood pressure with an intravenous injection of phenylephrine, 40.7% (22/54) of the LPBN units were inhibited and 27.8% (17/54) excited. Following orthodromic stimulation of the depressor area in the NTS, 55.6% (94/169) of the LPBN units showed an increase and 22.5% (38/169) a decrease in firing rates. Among the LPBN neurons antidromically activated by SFO stimulation, 2 units were inhibited by phenylephrine administrated i.v.; of the 8 units tested, when the NTS was stimulated, 6 were excited and 2 inhibited. The results suggest that the LPBN neurons may receive inhibitory or excitatory baroreceptive inputs from the NTS and then relay it directly to SFO.

Animals↗
PubMed1990

Effects of electrical stimulation of the central nucleus of the amygdala and the lateral hypothalamic area on the oval nucleus of the bed nuclei of the stria terminalis and its adjacent areas in the rat.

Our recent studies demonstrated that there are reciprocal connections between the oval nucleus (Ov) of the bed nuclei of the stria terminalis (BST) and the central nucleus of the amygdala (Ce) or the lateral hypothalamic area (LHA). The present experiments found that spontaneous unit discharges of 73 neurons in the Ov and its adjacent areas were modified in 58 neurons (79.45%) by focal brain stimulation in the Ce. After focal LHA stimulation, the spontaneous unit discharges of 23 (53.49%) of 43 Ov neurons, which could be influenced by focal Ce stimulation, were changed. Thirteen Ov neurons were antidromically activated by focal Ce or LHA stimulation. These results indicate that: (1) neuronal activities in the Ov and its adjacent areas can be modulated by Ce or LHA; (2) there are functional reciprocal connections between Ov and Ce or LHA; and (3) the Ce and LHA afferents converge upon some Ov neurons.

Action Potentials↗
PubMed1990

Substance P-like immunoreactive nerve fibers in the pars distalis of the anterior pituitary in the dog.

The pars distalis of the anterior pituitary is known to be regulated by hypothalamic hormones. Recently, we have discovered the presence of substance P-like immunoreactive nerve fibers in the pars distalis of the monkeys. Substance P-like immunoreactivity in the pars distalis of the dog was investigated in this study. A substantial amount of substance P-like immunoreactive nerve fibers with a large amount of varicosities were found. They were widely distributed in the gland, more abundant along its periphery. Most of them were closely related to the glandular tissue, some were located on vascular walls. Substance P-like immunoreactive nerve fibers were also found in the meningeal sheath of the anterior pituitary. They could be followed into the parenchyma of the gland.

Animals↗
PubMed1990

An electron microscopic study on substance P-like immunoreactive nerve fibers in the pars distalis of the adenohypophysis in the dog.

The pars distalis of the adenohypophysis has recently been proved to be innervated by substance P-like immunoreactive nerve fibers in the monkey and the dog. The present study investigated immuno-electron microscopically the morphology of these nerve fibers and their relationship to anterior pituitary gland cells in the dog. The nerve fibers were unmyelinated and varicose. Direct contacts between them and every cell type of the gland could be ascertained, including folliculostellate cells. Typical synapses were identified on somatotropes and corticotropes. Most of them were of asymmetrical type with round to oval small clear vesicles and scattered large dense-cored vesicles. Occasional symmetrical type synapses were also seen. The results imply that substance P-like immunoreactive nerve fibers have an effector role in the pars distalis of the dog.

Animals↗
PubMed1989

Studies on the cellular architecture of the bed nuclei of the stria terminalis in the rat: I. Cytoarchitecture.

The cytoarchitecture of the bed nuclei of the stria terminalis (BST) in the adult male rat was examined in the three standard planes of section, and the results were compared with the distribution of immunohistochemical staining for a variety of neuropeptides in a companion paper (Ju et al.: J. Comp. Neurol. 280:603-621, '89). It is clear that the BST is an extremely complex mass of gray matter that can be parcellated most clearly into anterior and posterior divisions, which are separated by a more-or-less vertical septum of fibers associated with the stria terminalis. The anterior division can be further parcellated into dorsal, lateral, and ventral areas, and each of these areas, along with the posterior division, can be thought of as containing more-or-less discrete nuclei embedded within a relatively undifferentiated region. Thus, we have recognized a central core in the anterodorsal area; oval, juxtacapsular, and rhomboid nuclei in the anterolateral area; and fusiform, dorsomedial, dorsolateral, magnocellular, and ventral nuclei in the anteroventral area. The most obvious cell groups in the posterior division include the principal, interfascicular, transverse, premedullary, and dorsal nuclei. Problems associated with defining the limits of the BST, and with comparing our results with the earlier literature, are discussed.

Animals↗
PubMed1989

Studies on the cellular architecture of the bed nuclei of the stria terminalis in the rat: II. Chemoarchitecture.

In a companion paper (Ju and Swanson; J. Comp. Neurol. 280:587-602, '89) we described a parcellation scheme for the bed nuclei of the stria terminalis (BST) that was based on cytoarchitectonic criteria. In the work reported here, antisera to the neuropeptides corticotropin-releasing hormone, neurotensin, galanin, substance P, and cholecystokinin were used to determine the extent to which immunostained neuronal cell bodies and presumed terminal fields are correlated with this cytoarchitectonic scheme in the adult male rat. The results confirm the validity of the cytoarchitectonic parcellation and provide additional chemoarchitectonic criteria for determining the (as yet still somewhat arbitrarily defined) border between the BST and the ventrally adjacent preoptic region, for distinguishing between the anterior and posterior divisions of the BST, and for identifying and distinguishing between the particular cell groups or nuclei within each division. The projections of each neuropeptide-containing cell group in various parts of the BST remain to be determined, as do the precise origins of the localized immunoreactive terminal fields identified here.

Animals↗
PubMed1989

Fluorogold as a retrograde tracer used in combination with immunohistochemistry.

The fluorescent dye Fluorogold has been recently introduced as a retrograde neuronal tracer that can be used in combination with immunohistochemistry. It has, however, lately been reported that immunohistochemical processes induced rapid photobleaching of Fluorogold. In the present study we prove that it is the water in the sections, and not the immunohistochemical processing itself, that is responsible for the photobleaching. This problem is easily corrected by using a 29:1 or 19:1 glycerine-PBS buffer mounting medium.

Animals↗
PubMed1989

The relationship of substance P-immunoreactive nerve fibers to thyrotropes and corticotropes in the pars distalis of the anterior pituitary in the monkey.

In our previous studies substance P-immunoreactive nerve fibers have been demonstrated in the pars distalis of the anterior pituitary in macaque monkeys, and they have been found to contact somatotropes. The present study investigated the relationship of the substance P-immunoreactive fibers to thyrotropes and corticotropes. Macaca mulatta monkeys were used. Sections of the anterior pituitaries were double immunostained with antisera against either substance P and human thyrotropin or substance P and human adrenocorticotropic hormone. Substance P-immunoreactive varicosities were found to be in close proximity to thyrotropes and corticotropes. It is therefore suggested that a direct neural factor may take part in the regulation of thyrotropin and adrenocorticotropic hormone secretion.

Adrenocorticotropic Hormone↗
PubMed1988

Co-internalization of the p55 and p70 subunits of the high-affinity human interleukin 2 receptor. Evidence for a stable ternary receptor complex.

The high-affinity IL-2-R complex is composed of at least two distinct IL-2-binding subunits, including p55 (Tac, IL-2-R alpha) and p70 (IL-2-R beta). Using a radiolabeled mAb specific for the p55 receptor subunit and cells expressing a homogeneous population of high-affinity binding sites, we demonstrate that p55 is co-internalized with p70 after IL-2 binding to the receptor complex. Endocytosis of p55 depends upon the presence of IL-2 in a form capable of effectively interacting with the p70 subunit. Whether IL-2 is required for high-affinity receptor assembly or triggering of the internalization of preassembled receptors remains unresolved. Together, these findings support the existence of a stable, high-affinity human IL-2-R membrane complex composed of at least the p55 and p70 receptor subunits and IL-2.

Binding Sites↗
PubMed1988

Serotonin-like immunoreactive fibers in the medial dorsal accessory group and the anterior fornical nucleus of the magnocellular neurosecretory system in the rat.

The area lateral to the stria medullaris and the fornix at the level of the interventricular foramen, an area known to be occupied by the medial dorsal accessory group and the anterior fornical nucleus of the magnocellular neurosecretory system, was found to be studded with serotonin (5-HT)-like immunoreactive (LI) varicosities. Double immunostaining with antisera against 5-HT and oxytocin (OXY) proved that the 5-HT-LI varicosities were in close proximity to the OXY-LI neurons in the medial dorsal accessory group and the anterior fornical nucleus. These nuclei were distributed more densely with 5-HT-LI varicosities than other cell groups in the magnocellular neurosecretory system.

Animals↗