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Biomedical subjects

H Kaiya

Publications and source records attributed to H Kaiya.

At least 73 records · Page 4Linked to original sources
PubMed1980

Ultrastructure of acetylcholinesterase synthesizing neurons in the neostriatum.

Acetylcholinesterase (AChE) ultracytochemistry with thiocholine method was studied in the rat neostriatum. AChE synthesizing neurons were identified by observing reappearance of the enzyme after application of an AChE inhibitor, DFP. Neurons in the neostriatum were classified into 6 types. All such types were demonstrated to synthesize AChE. Two types of efferent neuron (types III and IV) have shown a relatively large amount of AChE and resynthesized the enzyme in the earlier stage after DFP. A tentative model of the neuronal network in the neostriatum was schematically shown.

Acetylcholinesterase↗
PubMed1980

Neuromelanin, neuroleptics and schizophrenia: hypothesis of an interaction between noradrenergic and dopaminergic system.

On the assumption that neuromelanin content might be a parameter indicating neuronal activity in the catecholaminergic system, neuromelanin was measured microspectrophotometrically in the substantia nigra and the locus ceruleus of 12 brains of patients who had undergone neuroleptic therapy. Neuromelanin increased with age in both regions of 40 control brains. Although no significant difference in melanin content between medicated and control brains was seen, a high negative correlation (r = -0.79) was noted in melanin content between the substantia nigra and the locus ceruleus only in each medicated brain, especially in cases of schizophrenia. The possibility of noradrenergic and dopaminergic interaction is discussed.

Adult↗
PubMed1979

Distribution and origin of acetylcholinesterase activity in the capillaries of the brain.

Areas containing AChE-positive capillaries were mapped in the brain of the cat and the guinea pig. Regions with AChE-positive capillaries mostly also contain neuronal elements with AChE activity. Electron-microscopical cytochemistry revealed localization of AChE in basement membranes of endothelial cells and pericytes very often in continuity with activity of the extracellular space. Intraendothelial AChE activity was seen only in pinocytic vesicles. The vascular AChE is thought to be of neuronal origin since no cytochemical evidence has been obtained for a synthesis of this enzyme in endothelial or other non-neuronal cells in the CNS.

Acetylcholinesterase↗
PubMed1979

Creutzfeldt-Jakob disease--alteration in ganglioside sphingosine in the brain of a patient.

Gangliosides isolated from the brain of patients with Creutzfelt-Jakob (C-J) disease were analyzed. The ganglioside current was abnormally low, and the percentage distributions of individual gangliosides and the long-chain base compositions were abnormal. The C20-sphingosine contents of all the ganglioside fractions were low. Abnormalities in ganglioside long-chain bases in adult human brain have been reported previously only in patients with inherited metabolic disorders. These abnormalities in C-J disease seem to be closely related to the cause of the disease.

Brain Chemistry↗
PubMed1979

Ultrastructure of acetylcholinesterase containing striato-nigral neurons transporting HRP retrogradely.

The fine structure of striato-nigral efferent neurons, retrogradely labeled with HRP, was studied. The neuron showed a medium sized ovoid or tri-angular perikaryon. Short or medium lengthened granular endoplasmic reticula, having a tendency to wind and pile up in stacks were observed. This neurons corresponds to a type III neuron according to our classification [4,5]. The neuron showed reaction products, indicating AChE activity, in the granular endoplasmic reticula and plasma membrane.

Acetylcholinesterase↗
PubMed1979

Fine structure of target neurons of antischizophrenic drugs in the neostriatum--ultracytochemical observation of dopamine and acetylcholine interaction.

In order to show the fine structure of target neurons of antischizophrenic drugs in the neostriatum, acetylcholinergic neurons were identified by means of choline acetyltransferase (ChAc) and acetylcholinesterase (AChE) cytochemistry. Two types of neurons were revealed to have ChAc activity and at the same time to be synthesizing sites of AChE. It was observed that both types of neuron receive boutons containing ChAc positive synaptic vesicles at the soma and/or the dendrite. Moreover, both types of neuron were revealed to be postsynaptic sites of dopaminergic synapses from the fact that degenerated boutons after coagulation of the substantia nigra and boutons containing granular synaptic vesicles after incubation with alpha-methylnoradrenaline, contact the soma of the cholinergic neurons. It is speculated that both cholinergic neurons may be reciprocally influenced as in the case of motor neurons and Renshaw cells in the spinal anterior horn.

Acetylcholine↗
PubMed1978

Chlorpromazine causes vesicle population changes in the monoaminergic synapse of the rat caudate nucleus.

The population of monoaminergic synaptic vesicles in the rat caudate nucleus remained unchanged or slightly decreased 3 h after chlorpromazine (CP) administration, and clearly increased after 24 h. The diameter of synaptic vesicles became smaller when the vesicles increased. These findings suggest that CP causes presynaptic blocking in part of its actions and leads to a condition in which neural transmission is inactive. In the control animals, population of the vesicles tended to fluctuate following the circadian rhythm.

Animals↗
PubMed1977

Corticocerebellothalamic degeneration with chromatolytic neuronal swelling: a light and electron microscopic case study.

A 50-year-old woman showing psychoorganic syndrome, cerebellar symptoms, choreatic involuntary movements, Romberg's sign and epileptic fits over a period of 14 years, was neuropathologically studied. The calcarine and postcentral cortex, the medio-dorsal nucleus of the thalamus and the cerebellar cortex were affected with neuronal loss and astrocytic gliosis. Neurons in various regions showed chromatolytic neuronal swelling. Ultrastructurally, these chromatolytic neurons contained a large hollow core with numerous mitochondria, dispersed rough endoplasmic reticulum, degenerated cisternal structures and a few neurofilaments. Some neuronal mitochondria showed membranous trans-somal bridges composed of about 60 A parallel filaments with a spacing of about 80 A.

Brain Diseases↗
PubMed1977

Chlorpromazine induces population increase of synaptic vesicles in the rat hypothalamic ventromedial nucleus.

The population of synaptic vesicles per synaptic area in the hypothalamic ventromedial nucleus of rats treated with chlorpromazine (CP) for 3 days was compared with that of controls. In type I synapse, which contained 400-800 A small spherical vesicles (s-vesicles), together with 800-1200 A large spherical dense-cored vesicles (lc-vesicles), the population of s-vesicles increased 57.8% in the CP rats, In type II synapse, which contained only s-vesicles, the rate of increase among CP animals was 15.4%. Findings suggested that CP blocks the release of the vesicles from the presynaptic site or inhibits the transport function for biogenic amines through the presynaptic membrane, and type I synapse may be aminergic.

Animals↗
PubMed1976

[Atypical mitochondria and crystallines in chromatolytic neuronal swelling].

Chromatolytic neuronal swelling was observed in the various brain regions, e. g. precentral cortex, pons and anterior horn of the spinal cord etc., of a 50-year-old woman showing psycho-organic syndrome and various neurological symptoms over a period of 14 years. In these inflated, chromatolytic nerve cells, atypical mitochondrias and paracrystalline structures were seen. Atypical mitochondrias contained membranous trans-somal bridges composed of about 60 A parallel filaments with a spacing of about 80 A. Paracystalline structures consisted of 7-16 hexagonal lattices with electron-light dots 160 A in diameter and with 280 A spacing. The goniometer revealed another featue of the paracrystals, i.e., lamellar structures consisting of 4-10 parallel filaments 120 A thick with a spacing of 160 A. These paracrystals were compared with similar structures in physiological and pathological conditions and the significance of the atypical mitochondrias was discussed.

Crystallization↗