Pharamacological characterization of excitaory synaptic potentials in rat basolateral amygdaloid neurons
Journal
Synapse
Journal Volume
11
Journal Issue
1
Pages
1月9日
Date Issued
1992
Author(s)
Gean P.W.
Abstract
The pharmacological properties of synaptic responses in rat basolateral amygdaloid (BLA) neurons were studied using intracellular recording techniques. Three distinct types of synaptic potential were evoked by stimulation of the adjacent ventral endopyriform nucleus: 1) a fast excitatory postsynaptic potential (f-EPSP); 2) a late EPSP (1-EPSP) following the f-EPSP; and 3) a multiphasic hyperpolarization following the initial depolarizing potential. Superfusion of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), a selective non-N-methyl-D-aspartate (non-NMDA) receptor antagonist, blocked the f-EPSP in a concentration-dependent manner. The ED50 for this effect was around 4 microM. In the presence of CNQX, however, a small depolarizing potential remained. This residual depolarizing component was markedly enhanced on removing Mg++ from the perfusing medium and could subsequently be abolished by DL-2-amino-5-phosphonovaleate (DL-APV, 50 microM) indicating its mediation via NMDA receptor-coupled ionophore. The l-EPSP was reversibly blocked by DL-APV. These results suggest that the pyriform cortex-amygdala pathway is mediated through excitatory amino acids acting on non-NMDA as well as NMDA receptors located on the BLA neurons.
Type
journal article