Computer simulation of the pacemaker oscillations of thalamocortical cells.

Computer simulations of the spontaneous pacemaker oscillations observed in thalamocortical (TC) cells were performed using a biophysical model that included the low voltage activated, Ca2+ current, IT, and the mixed Na+/K+, inward rectifying current, Ih. The simulations accurately reproduced the waveform and voltage-dependence of the pacemaker oscillations, hence the transition from tonic firing to burst firing which is a peculiar feature of the electrical activity of TC cells both in vivo and in vitro. The results provide further support to the suggestion that IT and Ih are essential for the presence of the pacemaker oscillations, and indicate that our model is a useful tool for the study of spontaneous, low-frequency oscillatory activities in TC cells.