PubMed Health⌕ Search

Biomedical subjects

K Kitahama

Publications and source records attributed to K Kitahama.

At least 91 records · Page 5Linked to original sources
PubMed1988

Immunohistochemistry of tyrosine hydroxylase and phenylethanolamine N-methyltransferase in the human brain stem: description of adrenergic perikarya and characterization of longitudinal catecholaminergic pathways.

Using immunocytochemical method in conjunction with antibodies to tyrosine hydroxylase and phenylethanolamine N-methyltransferase, catecholaminergic cell groups and axon pathways are mapped in the human hind brain. Adrenergic perikarya are located mainly in the rostral medulla, as in lower animals, and contribute a subset of axons to the main longitudinal catecholaminergic bundle which runs through the medulla oblongata, pons and midbrain such as the dorsal part of the central nucleus of the medulla oblongata, the parvocellular reticular formation ventromedial to the facial nerve and ventrolateral to the locus coeruleus. Adrenergic terminals are present in the locus coeruleus and other medullary and pontine structures. The locus coeruleus contains only tyrosine hydroxylase-immunoreactive cells and appears to be the source of a discrete dorsal catecholaminergic bundle which runs through the central tegmental field just ventrolateral to the periaqueductal gray of the rostral pons and mesencephalon and which does not contain adrenergic axons. A ventral catecholaminergic bundle arising in the medullary cells does contain a subset of adrenergic axons in the mesencephalic tegmental field. These two longitudinal axon bundles run near each other in the mesencephalic reticular formation. Additional descriptions are provided of catecholaminergic axons near the dorsal and ventral surface of the human medulla.

Adrenergic Fibers↗
PubMed1987

First characterization of 5-hydroxytryptophan in rat brain by using specific antibodies.

DL-5-Hydroxytryptophan (5-HTP) was conjugated to bovine serum albumin and human serum albumin with glutaraldehyde (G). These conjugates made it possible to raise specific antisera in two rabbits. Their specificity and affinity were evaluated using an enzyme-linked immunosorbent assay and immunocytochemistry. For two antisera obtained, the most immunoreactive antigen was 5-HTP-G-protein, indicating that the same immune response was developed. The other conjugated indoleamines (5-methoxytryptophan-G-protein, tryptophan-G-protein) were poorly recognized or not at all (5-methoxytryptamine-G-protein, serotonin-G-protein, tryptamine-G-protein). These 5-HTP antisera enabled us to specifically visualize the precursor of serotonin in the raphe nuclei of G-fixed rat brains.

5-Hydroxytryptophan↗
PubMed1987

5-Hydroxytryptophan (5-HTP)-immunoreactive neurons in the rat brain tissue.

We demonstrated the presence of 5-hydroxytryptophan (5-HTP), the immediate precursor of serotonin (5-HT), in the rat brain tissue using a glutaraldehyde-coupled immunohistochemical technique. The immunoreactivity of 5-HTP was intensified in the colchicine-pretreated rat. The distribution of labelled cells was the same as for 5-HT-immunoreactive cells, but they were fewer in number.

5-Hydroxytryptophan↗
PubMed1987

Localization of tyrosine hydroxylase-immunoreactive neurons in the cat hypothalamus, with special reference to fluorescence histochemistry.

The present study examines the distribution and morphological characteristics of neurons containing immunoreactivity of tyrosine hydroxylase in the cat hypothalamus. We used the indirect immunoperoxidase technique on vibratome sections. Tyrosine hydroxylase-immunoreactive cell bodies were widely distributed in discrete regions of the cat hypothalamus. Several principal cell groups were identified. They were seen in the posterior and dorsal hypothalamic areas, zona incerta, dorsomedial and lateral hypothalamic areas, arcuate nucleus, periventricular nucleus, paraventricular nucleus, and an area of the tuber cinereum and preoptic area. These cells presented two different morphological characteristics; small with two to three short processes and medium to large, multipolar with three to five long dendritic trees. The atlas is presented in twelve cross-sectional drawings of the cat hypothalamus from the level A8.5 to A15 of the Horsley-Clarke stereotaxic planes. We also examined the distribution of hypothalamic catecholamine fluorescent neurons by using the aqueous aldehyde method in combination with glyoxylic acid applied to vibratome sectioned tissues, which improves sensitivity. Comments are made on the relative localizations of the tyrosine hydroxylase-immunoreactive and aldehyde-induced histofluorescent cells, as well as on species differences between the cat, rat, and mouse.

Animals↗
PubMed1987

Immunohistochemical evidence for the adrenergic medullary longitudinal bundle as a major ascending pathway to the hypothalamus.

Three weeks after unilateral electrolytic lesion of the longitudinal axon bundle in the medulla oblongata of the rat, we observed a decrease in the number of phenylethanolamine-N-methyltransferase (PNMT)-immunoreactive (IR) nerve fibers in virtually all the regions of the diencephalon ipsilaterally to the lesion, especially in the dorsomedial nucleus and the paraventricular nucleus of the hypothalamus. These results indicate that the hypothalamic PNMT-IR terminal-like fibers originate in the ipsilateral medulla oblongata presumptive adrenaline-containing (Ad) neurons especially through ascending projections provided in majority by the longitudinal axon bundle. Further, no PNMT-IR cell bodies were detected in the hypothalamus even after colchicine treatment.

Adrenergic Fibers↗
PubMed1987

Visualization of tyrosine hydroxylase-immunoreactive neurons in the cat dorsal motor vagal cells after treatment with parachlorophenylalanine.

We examined tyrosine hydroxylase-immunoreactive (TH-IR) neuronal structures in the cat dorsal motor nucleus of the vagus (DMV) and its adjacent regions. We identified only a few in the caudal part of the DMV and no TH-IR cells at all in its rostral portion. However, after treatment with parachlorophenylalanine (PCPA), numerous TH-IR perikarya were visualized in the DMV. Comments are made on the central catecholamine regulation and the possible influence of serotonin afferents on this nucleus.

Animals↗
PubMed1987

Immunohistochemical evidence for the adrenergic medullary longitudinal bundle as a major ascending pathway to the locus coeruleus.

The present study describes the first experimental evidence for a direct projection of the medulla oblongata adrenergic (Ad) neurons to the rat pontine structures by using the indirect immunoperoxidase technique. Three weeks after unilateral electrolytic lesion of the longitudinal axon bundle in the medulla oblongata, the morphological changes of the phenylethanolamine-N-methyltransferase (PNMT)-immunoreactive (IR) structures located in the rat brainstem have been analysed. In the lesioned rats we observed a decrease in the number of PNMT-IR structures in virtually all regions of the brainstem ipsilateral to the lesion, especially in the locus coeruleus (LC). These results indicate that the PNMT-IR terminal-like fibers of the LC are derived from the ipsilateral medulla oblongata Ad neurons and are mainly provided by the longitudinal axon bundle.

Adrenergic Fibers↗
PubMed1987

Distribution of two types of monoamine oxidase-containing neurons in the cat medulla oblongata demonstrated by an improved histochemical method.

The topographic distribution of cells containing monoamine oxidase, the enzyme which deaminates amines, was studied in the cat medulla oblongata. By means of enzyme histochemistry using a new coupled peroxidation method, monoamine oxidase activity was demonstrated in the somata, dendrites and fibers. Type A monoamine oxidase, inhibited by clorgyline but not deprenyl, were localized in the cells distributed in the ventrolateral and dorsomedial medulla where catecholaminergic neurons are present. Type B monoamine oxidase-positive cell bodies were identified in the regions containing serotonergic neurons. Furthermore, we found an intense activity of type A monoamine oxidase in many cells of the dorsal motor nucleus of the vagus of the rostrocaudal extent, and more rostrally in the nucleus parvocellularis where few or no aminergic neurons have been described.

Animals↗
PubMed1987

Effects of electrolytic lesion of hypothalamic paraventricular nucleus and its related areas on the sleep waking cycle in the cat.

In order to study putative hypothalamic mechanisms of sleep waking cycle regulation we destroyed, by electrolytic coagulation, a large part of the medial hypothalamus overlapping the paraventricular nucleus in 6 adult cats. We never observed any modification of light slow wave sleep. Three of the six cats presented no paradoxical sleep (PS) impairment, despite an almost total destruction of neurophysin-immunoreactive cells of PVN in two cats and marked signs of diabetes insipidus in the third. Further, in the other three animals a statistically significant decrease of daily quantities of PS and deep slow wave sleep (SWS2) were related to an extensive destruction of the anterior hypothalamic area. These results suggest lack of influence of the PVN in sleep regulation and an involvement of the anterior hypothalamus in the onset of SWS2 and PS.

Animals↗
PubMed1986

Biochemical evidence for an interaction between adrenaline and noradrenaline neurons in the rat brainstem.

In this study, we sought to determine if there was an interaction between the C2 adrenaline-containing (A) neurons of the rat medulla oblongata and the noradrenaline-containing (NA) cell bodies of the locus coeruleus (LC). For this purpose, the biochemical response of the NA cell bodies of the LC after a lesion of the C2 region was studied by using as markers the in vitro activities of the catecholamine synthesizing enzymes: tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH) and phenylethanolamine-N-methyltransferase (PNMT). An increase in TH activity, not associated with any change in DBH or PNMT activity, was found in the LC (+104%, P less than 0.001) 4 days after a bilateral electrolytic lesion (3 mA for 5 s) of the C2 region. Conversely, the electrolytic lesioning of the neighboring A2 region of NA neurons did not modify the TH activity of the LC. These results suggest the existence of an ascending adrenergic inhibitory control of the NA cell bodies of the LC.

Afferent Pathways↗
PubMed1986

Demonstration of monoamine oxidase type B in serotonergic and type A in noradrenergic neurons in the cat dorsal pontine tegmentum by an improved histochemical technique.

Application of a diaminobenzidine-coupled peroxidation method to monoamine oxidase (MAO) histochemistry demonstrates a detailed morphology of MAO-containing perikarya, dendrites, axons and fibers in the dorsal pontine tegmentum of the cat, sectioned with a vibratome. Further, utilization of specific inhibitors, deprenyl and clorgyline, also provides evidence that serotonergic neurons contain exclusively MAO-B and catecholaminergic ones contain MAO-A.

Animals↗
PubMed1986

Neonatal monosodium glutamate dosing alters the sleep-wake cycle of the mature rat.

Alterations of the sleep-wake cycle have been studied in male adult rats after neonatal administration of monosodium glutamate (MSG; 4 X 4 mg/g body wt.). Results indicated that MSG treatment caused: an almost complete disappearance of ACTH and alpha-MSH immunoreactive (IR) perikarya in the rostral part of the arcuate nucleus; an increase in total sleep duration with a more pronounced effect on paradoxical sleep. Regarding circadian rhythmicity there was a trend to a decomposition of the 24 h period into ultradian components (12 h, 8 h, 6 h harmonics). The participation of pro-opiomelanocortin peptides in sleep regulation is discussed.

Activity Cycles↗
PubMed1986

Distribution of PNMT-immunoreactive neurons in the cat medulla oblongata.

The distribution and morphology of presumptive adrenaline neurons in the cat medulla oblongata were studied in conjunction with the indirect immunoperoxidase technique utilizing antibody raised against bovine adrenal phenylethanolamine-N-methyltransferase (PNMT), an enzyme which converts noradrenaline to adrenaline. Small PNMT-immunoreactive (IR) perikarya are located in the dorsomedial part of the medulla (C2 group) extending from P17 to P12, and larger ones in the ventrolateral part (C1 group) from P11 to P9 of the caudorostral extent. In the rostral medulla (P11-10), larger cells extended more dorsally in the lateral tegmental field, where only a few catecholamine cells are localized. No midline PNMT-IR cells were identified corresponding to C3 cell group in the rat. Distinct longitudinal PNMT-IR axon bundles can be traced through the dorsal part of the lateral tegmental field. Comments are made on the relative localizations of the PNMT-IR and DBH-IR cells, as well as on species differences in comparison with the results reported in the rat.

Adrenal Glands↗
PubMed1986

Early development of serotonin neuron in the rat brain as studied by immunohistochemistry combined with tryptophan administration.

Early differentiation of serotonin (5HT) neurons was studied by an immunohistochemical technique in the metencephalon of rat embryos of CR lengths of 6 mm to 22 mm. Pregnant dams were treated with tryptophan (100 mg/kg) and pargyline (100 mg/kg). The synthesis of 5HT after tryptophan loading first occurs at any stage in the premature cells located in the ependymal layer. The cells appearing at the later embryonic stage begin 5HT synthesis at an earlier developmental stage of neurons with greater capacity to produce 5HT. Two different processes were revealed for the development of 5HT neurons. Most of the 5HT neuroblasts first give off axonal processes and then begin to migrate toward the mantle layer with reversed rotation. Some of the 5HT neuroblasts, later generated in the rostral pons in particular, display characteristic transformation without notable migration. After sending out of axonal processes ventrally, the apical processes are transformed into a number of dendritic processes directed toward the ventricular surface.

Animals↗
PubMed1985

Adrenergic neurons in human brain demonstrated by immunohistochemistry with antibodies to phenylethanolamine-N-methyltransferase (PNMT): discovery of a new group in the nucleus tractus solitarius.

Adrenaline neurons in human brain were demonstrated by immunohistochemistry using antibody to phenylethanolamine-N-methyltransferase (PNMT), the final enzyme in the pathway of adrenaline synthesis, using fixed frozen sections and a highly sensitive free floating technique which utilizes metallization. Small densely packed PNMT-immunoreactive neurons were observed to form a nucleus lying just ventrolateral to the area postrema and in the dorsal part of the nucleus tractus solitarius. Larger adrenergic neurons were also present in and around the lateral reticular nucleus and in relationship with the dorsal motor nucleus of the vagus in regions equivalent to the C1 and C2 groups in rats. Longitudinally oriented PNMT-positive axons constitute a subset of tyrosine hydroxylase-immunoreactive axons in the dorsomedial reticular formation.

Adrenergic Fibers↗