Figure 5.

Unmasking of excitatory components during BS responses matching the timing of inhibitory components during low isoflurane conditions. Averaged evoked responses of a cortical neuron (area 5) to thalamic (LP) stimulation (n = 25). A1, Responses of the same neuron: before BS induction (under low isoflurane), during BS (high isoflurane), and after recovery from BS (return to low isoflurane). During the BS period a depolarizing potential replaces the inhibitory component of the control period. This change is also apparent in the nearby recorded field potential (FP). All stimuli were applied during the suppression period. A2, The BS-related depolarizing event displayed voltage dependence and increased with membrane hyperpolarization. B, Similar patterns in another neuron exhibiting an excitatory BS component expressed early after the initial excitatory response.