Significance of random neuronal drive

Effectively random firing occurs frequently in the brain. Random components of neuronal drive are therefore often major influences on activity. We des cribe here how level of drive, inhibitory/excitatory balance, correlation b etween input streams, EPSP/IPSP characteristics, the nature of the postsyna ptic neuron all affect pattern and level of firing, the influence often int eracting in complex ways. Random firing might also be instrumental in facil itating synchronized firing. These factors are possibly important elements of the mechanisms by which some neural networks encode information. Clarify ing them might therefore facilitate a deeper understanding of the nature of the neural code. (C) 2001 Published by Elsevier Science B.V.