To import the random processes library:
from brian.library.random_processes import *
For the moment, only the Ornstein-Uhlenbeck process has been included. The function OrnsteinUhlenbeck() returns an Equations object. The following example defines a membrane equation with an Ornstein-Uhlenbeck current I (= coloured noise):
eqs=Equations('dv/dt=-v/tau+I/C : volt')
eqs+=OrnsteinUhlenbeck('I',mu=1*nA,sigma=2*nA,tau=10*ms)
where mu is the mean of the current, sigma is the standard deviation and tau is autocorrelation time constant.