Figure 11.

SK2 channels do not increase burst firing propensity. Current ramps of variable slope (duration varying from 2 to 10 s) were simulated and injected into a computational model of a thalamic relay cell, including both T-type calcium current and SK current. Before the injection of the depolarized current ramp, the cell membrane voltage was maintained at a potential of −80 mV for 2 s to ensure proper de-inactivation of T-type calcium channels. All cells were depolarized sufficiently by the current ramp to elicit regular tonic firing. A, The addition of SK2 channels to our model of medium and high burst propensity neurons (illustrated in Fig. 9) decreased burst firing propensity. B, With the same SK2 channel density used in A, T-channel density needed to be increased up to 3 × 10⁻⁴ cm/s to match our in vivo recordings.