Figure 1. Simultaneous, triple whole-cell voltage recording from pyramidal neurones and two classes of interneurone.

A, schematic drawing of the recording configuration. A presynaptic L2/3 pyramidal neurone (P) was stimulated by brief pulses of intracellular current injection. Simultaneous whole-cell voltage recordings were made of unitary EPSPs from a bitufted (B) and a multipolar (M) neurone. B, simultaneous recordings of presynaptic APs evoked in a pyramidal neurone (top) and the unitary EPSPs in a bitufted and a multipolar neurone. Five consecutive traces recorded in the bitufted (left) and multipolar (right) neurone are shown. Lines above the records indicate the time of presynaptic APs in the train. The lowermost traces represent averages of 100 sweeps. The ratio of peak amplitudes of the second and first mean EPSP (EPSP2/EPSP1) was 1.43 in the bitufted neurone and 0.67 in the multipolar neurone.