Firing rate adaptation to changes in input variance.

(A) Top: Noisy input current with two standard deviations: 6+ nA,  = 1 or 2 nA. Bottom: The firing rate to noisy input current calculated from 100 trials, . (B) Top: Time varying noisy input current. 5+ nA,  = 1, 4, 2, 1, 2, 1, 4 and 2 nA, consecutively, and the noise is filtered with an alpha function with ms. Bottom: Instantaneous firing rate in response to the input current for (blue) and (black). For both ms and ms.