Figure 8.

Blocking visual responses in the Ipc abolishes visual responses in the SLu. A, Traces showing multiunit paired recordings in the SLu and Ipc in response to three consecutive sweeps of a bright spot (2 deg, 16 deg/s, 1.5 s duration) through the overlapped RFs of both recording sites, as depicted in C. B, Same paired recordings after local blockade of the Ipc with CNQX (0.2 mm). Rectangles demarcate the RF of the Ipc recording site before inactivation. Note that some spontaneous activity remains in the SLu along with some visual responses to stimulation outside the RF of the inactivated site. D, Average drop of activity in the SLu in six experiments in four animals. In each experiment, activity was estimated as the spike count within the rectangle to five repetitions of the three sweeps represented in C (15 sweeps total).