Fig. 6.

Strong corticothalamic activity enhance the burst discharge of PGN cells. A, Multiunit recording in the perigeniculate nucleus. Short-duration burst discharges of a PGN cell during spindle waves (asterisk; 2 top traces) are transformed in prolonged discharges during the rhythmic stimulations (7 shocks at 140 Hz; 400 msec interval) of corticothalamic axons (2 bottom traces). B, Increasing the number of shocks of stimulation (respectively 2, 5, and 7) increases the intensity of discharges recorded in the PGN. C, Same protocol as inB performed intracellularly for one, two, three, and five shocks. Average for five shocks response consists of 15 traces.