Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P80404 (GABA transaminase)
 786 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Implantation of cobalt-agar rods into the visual cortex of 16 adult rats induced in some of the animals epileptiform bioelectrical activity and provoked in all of them histological and histochemical changes in the region of the implantation (primary focus) as well as in some ipsilateral projection sites of the visual cortex (secondary foci). The changes within the secondary foci are demonstrated in the Corpus geniculatum laterale, pars dorsale (dLGN), by means of 18 histochemical and 5 histological methods. Together with the appearance of hyperactive and degenerating neurones combined with neuronophagy and diminution of the number of synapses a marked gliosis developed, especially an increase of microglia. The destruction of the tissue induced a depression of energy and transmitter metabolism and intensified lytic processes. This is confirmed by the decreased activities of LDH, SDH, GPDH, G6PDH, NAD(P)H-TR, GABA-T and GDH and the increased activity of acid phosphatase in the neuropil of the secondary foci. Single hyperactive nerve and glial cells were accented by high activities of those enzymes which had a reduced activity in the neuropil. Since in our experiments agar-rods without cobalt never induced histological or histochemical changes in subcortical grisea of the visual system, the secondary foci seem to result from the direct influence of the cobalt, migrating in the corticothalamic projection pathway and identifiable in the dLGN by the TIMM technique.
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PMID:[Morphologic and histochemical changes in the secondary focus following cobalt-induced epileptogenic bioelectrical activity of the visual cortex in the adult rat]. 393 55

1 The synthesis of two analogues of gamma-aminobutyric acid (GABA), beta-chloro GABA and beta-phenyl GABA is described.2 The activity of brain GABA aminotransferase was inhibited by beta-chloro GABA (5.7 x 10(-5)M) and beta-phenyl GABA (4.6 x 10(-3)M) in a competitive manner with GABA.3 beta-Chloro GABA exhibited 50% of the inhibitory activity of GABA in blocking the discharge of the crayfish stretch receptor neurone; beta-phenyl GABA had no detectable effect.4 Injection of beta-phenyl GABA (200 mg/kg) into normal or epileptic cats (cobalt) caused the appearance of synchronized slow-wave EEG activity.5 Administration of beta-chloro GABA (200 mg/kg) to epileptic cats (cobalt) produced a temporary diminution or abolition of epileptic discharges while causing no alteration in normal EEG activity.6 beta-Chloro GABA and beta-phenyl GABA had no effect on the concentrations of catecholamines or of amino acids in mouse brain.7 The results suggest that both beta-chloro GABA and beta-phenyl GABA may pass the blood-brain barrier.
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PMID:Biological actions in vivo and in vitro of two gamma-aminobutyric acid (GABA) analogues: beta-chloro GABA and beta-phenyl GABA. 415 85

Putative GABAergic neurons in the outer retina of the Texas channel catfish, Ictalurus punctatus, were studied using autoradiographic, biochemical and electrophysiological techniques. A red cone horizontal cell was found to accumulate exogenous GABA in the presence of red light. GABA could be released from these cells with high K+ Ringers solution. The release was only partially blocked by Co2+ and therefore may be only partially Ca2+ dependent. The red cone horizontal cells were found to contain significant activities of L-glutamic acid decarboxylase and GABA transaminase, the enzymes responsible for GABA synthesis and degradation respectively. These data suggest that catfish red cone horizontal cells are GABAergic. To substantiate this, recordings were made from photoreceptors and horizontal cells during the superfusion of the GABA blocking agents bicuculline methochloride or picrotoxin. These agents modified the cone responses in the manner specified if they were blocking the feedback pathway from horizontal cells to cones. Thus it is likely that the horizontal cells are using GABA as the transmitter in the feedback pathway. In addition, the GABA blocking agents were found to interfere with changes in horizontal cell responses which occur during light adaptation.
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PMID:The identification and some functions of GABAergic neurons in the distal catfish retina. 674 Sep 69