Antagonism of lateral olfactory tract synaptic potentials in rat prepyriform cortex slices.

Dose-response data were collected for the inhibition of the monosynaptic excitatory input onto prepyriform neurons from fibers of the rat lateral olfactory tract, using the potent antagonists of excitatory transmission, L(+)-2-amino-4-phosphonobutyrate (L(+)-AP4), kynurenate, N-(p-chlorobenzoyl)piperazine-2,3-dicarboxylate, and N-(p-bromobenzoyl)piperazine-2,3-dicarboxylate. Kynurenate and the piperazine derivatives blocked up to 80% of the synaptic response at doses of 1000 microM, with single-affinity dose-response curves. L(+)-AP4 blocked only 50% of the synaptic response at a dose of 1000 microM, with a multicomponent dose-response curve.