A Model of Target Selectivity and Hypersensitivity in the Electrosensory System of Sharks using Rapidly Varying Effective Synaptic Strengths

摘要

Sharks hunt using a passive electric sense. The sensitivity of primary afferent electrosensory neurons appears to be well below what is required to explain the observed behavioural sensitivity. But secondary neurons are more sensitive and selective for signals resembling those generated by prey, while being less sensitive to other stimuli. We have found that the effective weights of synapses between primary and secondary electrosensory neurons vary rapidly in an activity-dependent manner. In this paper we describe a computer model that shows how these rapid variations in synaptic weights may contribute to target selectivity and hypersensivity of secondary electrosensory neurons.