GABAERGIC INHIBITORY INPUTS TO SUBFORNICAL ORGAN NEURONS IN RAT SLICEPREPARATIONS

Citation
K. Inenaga et al., GABAERGIC INHIBITORY INPUTS TO SUBFORNICAL ORGAN NEURONS IN RAT SLICEPREPARATIONS, Brain research, 705(1-2), 1995, pp. 85-90
Citations number
24
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences
Journal title
ISSN journal
0006-8993
Volume
705
Issue
1-2
Year of publication
1995
Pages
85 - 90
Database
ISI
SICI code
0006-8993(1995)705:1-2<85:GIITSO>2.0.ZU;2-O
Abstract
To investigate GABAergic inhibitory inputs to neurons of the subfornic al organ (SFO), intracellular recordings were made in rat brain slice preparations. Inhibitory postsynaptic potentials, which occurred spont aneously or were evoked by focal electric stimulation, had reversal po tentials of approximately - 60 mV, and were almost totally abolished b y the GABA(A) antagonists bicuculline at 3-100 mu M or picrotoxin at 5 0 mu M. Following the application of bicuculline or picrotoxin, the re sting membrane potentials were decreased by 4-8 mV. GABA at 10-100 mu M and the GABA(A) agonist muscimol at 1-100 mu M decreased the membran e resistance and the firing rate in all neurons tested. The reversal p otential of the response to muscimol was similar to that for inhibitor y postsynaptic potentials. The actions of muscimol persisted in the pr esence of 1 mu M tetrodotoxin, implying that muscimol must act directl y on the recorded neurons. These results suggest that there is a tonic inhibitory GABAergic input to SFO neurons which are mainly mediated t hrough GABA(A) receptors.