Fig. 7.

Facilitation of the monosynaptic PSP from an LE neuron to an LFS neuron during classical conditioning.A, Examples of the monosynaptic PSP produced in an LFS neuron by intracellular stimulation of an on-field (A₁) and off-field (A₂) LE neuron ∼10 sec before the siphon tap on the pretest and the final post-test after paired and unpaired training. B, Average modulation of the monosynaptic PSPs during paired and unpaired training. Paired training produced a greater increase than unpaired training in the amplitude and area of PSPs from LE neurons that fired during the siphon tap (on-field; B₁). The increase in PSPs from on-field LE neurons during paired training was also significantly greater than the increase in PSPs from LE neurons that did not fire during the siphon tap (off-field;B₂). The average values on the pretest were 10.8 mV and 820 mVmsec (paired, on-field), 13.0 mV and 1040 mVmsec (unpaired, on-field), 10.6 mV and 633 mVmsec (paired, off-field), and 14.2 mV and 1031 mVmsec (unpaired, off-field), not significantly different by ANOVAs.