Figure 3.

L-AP4 differentially affects transmitter release from terminals arising from an individual axon that contacts different cell types. (A) Voltage and current traces: action potentials triggered by intracellular current pulses in a presynaptic CA3 pyramidal cell (1) evoked unitary EPSCs in a monosynaptically connected alveus-oriens interneuron (2). L-AP4 (50 μM) reversibly depressed the response. The monosynaptic response between the same presynaptic pyramidal cell and a subsequently recorded postsynaptic pyramidal cell (3) was not affected by L-AP4. The traces are composed of five superimposed sweeps. Plots: time course of this experiment for the amplitudes of the EPSCs; (Insets) EPSC latency histograms. (B) Summary graphs (n = 3; bin size: 3 stimuli). In one experiment, the postsynaptic cells were recorded in the reverse order.