FURTHER CHARACTERISTICS OF LONG-TERM POTENTIATION IN PIRIFORM CORTEX

Mechanisms for the induction and expression of long-term potentiation (LTP) were studied in slices of piriform cortex. Cooperativity among a fferent inputs as a controlling factor for induction of LTP was tested by pairing stimulation of one input that normally does not induce LTP with stimulation of another input. Combined stimulation, given either to two weak inputs with simultaneous bursts or by pairing single puls es with bursts, did effectively induce LTP. Tests for expression of LT P by NMDA vs. non-NMDA receptors indicated that non-NMDA receptor-medi ated responses expressed much greater LTP than NMDA receptor-mediated responses. Ratios for paired-pulse facilitation and depression were no t altered after induction of LTP. These characteristics are comparable to those exhibited by synapses in the CA1 field of hippocampus. (C) 1 994 Wiley-Liss, Inc.