TITLE Ornstein-Uhlenbeck fluctuating current : no checking for tau = 0 UNITS { (nA) = (nanoamp) (mV) = (millivolt) } NEURON { POINT_PROCESS Ifluct8 NONSPECIFIC_CURRENT i RANGE i0, i1, tau, std, deriv } PARAMETER { i0 = 0.0 (nA) tau = 2 (ms) std = 0.2 (nA) } ASSIGNED { v (mV) i (nA) deriv (nA/ms) } STATE { i1 (nA) } INITIAL { i1 = i0 i = i0 } BREAKPOINT { SOLVE states METHOD cnexp i = i1 } DERIVATIVE states { deriv = (i0 - i1)/tau + sqrt(2*std^2/tau) * normrand(0,1) i1' = deriv } PROCEDURE new_seed(seed) { set_seed(seed) VERBATIM printf("Setting random generator with seed = %g\n", _lseed); ENDVERBATIM }