GENESIS: Documentation

Related Documentation:

De Schutter: Purkinje Cell Model

PIC

Figure 1: Activation and inactivation properties of the delayed rectifier current (Kdr, —) in the model. Seady-state activation and inactivation vs. voltage are plotted at the left, the time constants of activation and inactivation(τm and τh) vs. voltage in the middle (Note: Semilogarithmic scale), and a simulation of representative voltage-clamp currents at the right, obtained from a spherical cell and assuming a complete block of all other channels. The voltage clamps simulate steps from a holding potential of -110 to -70 mV up to 0 mV in 10 mV increments. The voltage-clamp current amplitude has been scaled arbitrarily because we mainly wanted to demonstrate the current kinetics.

Delayed Rectifier (Kdr)

The Purkinje cell delayed rectifier (Kdr) is responsible for the repolarization of somatic action potentials. Whole-cell voltage-clamp recordings (Fig. 9 in [2]) and patch-clamp recordings (Fig. 9 in [1]) of the Kdr current are available but incomplete. The I - V relations of the currents in both reports are very similar. In the current model we have used the published equations for Kdr current in bullfrog sympathetic ganglion cells [3] because both the I - V curve and the steady-state inactivation (Fig. 2E) of the bullfrog data are comparable with the data from [2].

References

[1]   B Gähwiler and I Llano. Sodium and potassium conductances in somatic membranes of rat purkinje cells from organotypic cerebellar cultures. Journal of Physiology (Lond.), 417:105–122, 1989.

[2]   T Hirano and S Hagiwara. Kinetics and distribution of voltage-gated Ca, Na, and K channels on the somata of rat cerebellar Purkinje cells. Pfluegers Archiv, 413:463–469, 1989.

[3]   Koch C Yamada W and Adams P R. Multiple channels and calcium dynamics. In Koch C and Segev I, editors, From Synapses to Networks, pages 97–133. MA: MIT Press, 1989.