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Pharamacological characterization of excitaory synaptic potentials in rat basolateral amygdaloid neurons
Author(s) -
Gean PoWu,
Chang FangChia
Publication year - 1992
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/syn.890110102
Subject(s) - neuroscience , basolateral amygdala , chemistry , amygdala , biology
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 ED 50 for this effect was around 4 m̈M. 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 m̈M) 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.