GETTING THE MOST OUT OF NOISE IN THE CENTRAL-NERVOUS-SYSTEM

Rather than merely a nuisance, noise in biological systems is a useful property, Before patch-clamp methods were invented, analysis of membr ane current noise provided the first solid, if indirect, evidence for the existence of ion-conducting pores with discrete conductance levels ,Although supplanted by single-channel recording techniques for most t asks, analysis of current membrane noise remains useful for certain pr oblems, such as determining the properties of channels with rapid kine tics that open with a high probability and desensitize, channels local ized at synapses, channels with an unusually low unitary conductance a nd open-channel noise, In addition, the role of noise in information p rocessing in the CNS is increasingly being recognized, In this article , we summarize the analysis of current membrane noise with an emphasis on what the technique is still useful for, and discuss the role for n oise in information processing.