Fig. 3.

Muscimol (100 μM) effects on thalamocortical vs. intracortical components of CF-evoked current sinks in layers 2/3, 4, and 5/6. A: example CSD profiles showing effects of control (ACSF, left) or muscimol (100 μM, right) microapplication; tone onset at beginning of plot, color scale as in Fig. 1. B: control injections had no effect on spontaneous fluctuations (left), current sink onset latencies (center), or response amplitudes (right; response amplitudes in B and C normalized to predrug peak values). C: muscimol reduced spontaneous fluctuations in all layers (left), had no effect on current sink onset latencies (center), and reduced peak response amplitudes in layers 2/3 and 4 but did not affect initial response amplitudes in any layer or peak amplitude in layer 5/6 (right).