SIMULATION OF INTERMITTENT ACTION-POTENTIAL FIRING IN THALAMOCORTICALNEURONS

THALAMOCORTICAL neurons are capable of displaying complex electrophysi ological behaviour, such as low- and high-frequency oscillations, beca use of their large number of different membrane channels. Recent exper imental results have provided direct evidence on the involvement of hi gh-threshold Ca2+ currents (I-HVA) in the genesis of the high-frequenc y oscillations that underlie intermittent action potential firing. Com plementing these findings, we now show by means of a biophysical model of a thalamocortical neuron how the interaction of I-HVA with a Ca2+- activated K+ current which is also present in these neurons may genera te this activity via intracellular Ca2+ processing.