Presynaptic alteration of [3H]GABA transport in hippocampus by amygdala kindling.
gamma-Amino[2,3-3H]butyric acid ([3H]GABA) transport was investigated in hippocampal synaptosomes prepared from amygdala kindled rats. Kindling enhanced [3H]GABA uptake by 10-20%, while the Km of uptake and the kinetics of the release were unchanged. The dose response curve of the inhibition of [3H]GABA uptake by veratridine was altered by kindling: the K0.5 of inhibition and the Hill number increased and the curve became biphasic after a long period of stimulations. This effect was interpreted in terms of a modification of the functioning of the presynaptic fast Na+ channels which initially become more resistant to depolarization. In the long term, it appears that new Na+ channels develop that are more sensitive to the action of veratridine.
D000679:Amygdala / Q000503:physiopathology; D000818:Animals; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D007696:Kindling, Neurologic; D007700:Kinetics; D008297:Male; D008564:Membrane Potentials; D051381:Rats; D011919:Rats, Inbred Strains; D013569:Synapses / Q000378:metabolism*; D013574:Synaptosomes / Q000378:metabolism; D014701:Veratridine / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D005680:gamma-Aminobutyric Acid; D014701:Veratridine