CONSISTENCY IN NERVOUS SYSTEMS - TRIAL-TO-TRIAL AND ANIMAL-TO-ANIMAL VARIATIONS IN THE RESPONSES TO REPEATED APPLICATIONS OF A SENSORY STIMULUS IN APLYSIA

What is the internal noise in a nervous system? We studied this questi on by determining the trial-to-trial consistency of the neuronal respo nse in the abdominal ganglion of Aplysia californica. Because our volt age-sensitive dye recordings detected the spike activity from a large fraction of the neurons in the ganglion, these results provide a reaso nably complete characterization of the consistency of the response to a sensory stimulus. The consistency of each neuron was evaluated by th e number and timing of spikes in the response.