Fig. 6.

Frequency response of thalamic cells at high-dose levels shows that entrainment is constrained to the α-range. (A) Power spectrum of thalamic cell spiking in response to random excitation. The interspike intervals of the excitation are drawn from a uniform distribution. (B) Thalamic cell spiking frequency in response to periodic excitation at different frequencies (n = 20). As a result of the time scales of the inhibition and intrinsic currents, the thalamus always responds near 11 Hz. (C) In the absence of cortical excitation, TC-RE cells produce waxing and waning oscillations similar to the thalamic spindles modeled by Destexhe et al. (15, 20).