Figure 11. Simulations addressing the role of desensitization.

For the α1β3γ2L isoform, the role of fast and slow desensitization in shaping the current time course was assessed. A, using the optimized α1β3γ2L kinetic model, a simulated current was generated by a 2 ms application of 1 mM GABA. B, a non-desensitizing current exhibited a larger peak amplitude and deactivated with a biexponential time course. C, the removal of fast desensitization (D_f) increased the peak current amplitude and shortened the slow phase of deactivation. D, the removal of slow phases of desensitization (D_i and D_s) increased the magnitude and duration of the slow phase of deactivation. E and F, varying the rate of entry into and exit from D_f by 5-fold altered the shape of the deactivation time course. The original current time course is also shown (dotted line).