Functional GABA(A) receptors on rat vagal afferent neurones

Abstract

1. In the present study, in vitro electrophysiology and receptor autoradiography were used to determine whether rat vagal afferent neurones possess γ-aminobutyric acid (GABA)(A) receptors. 2. GABA (1-100 uM) and isoguvacine (3-100 μM) caused a concentration-dependent depolarization of the rat isolated nodose ganglion preparation at room temperature. When applied to the tissue 20 min before the agonist, SR95531 (3 μM) and bicuculline (3 μM) caused a parallel shift to the right of the GABA and isoguvacine concentration-response curves, yielding shifts of 81 fold and 117 fold for SR95531 and 4 fold and 12 fold for bicuculline, respectively. 3. Baclofen (10 nM-100 μM) was unable to elicit a depo..