Electrosensory Transduction: Comparisons Across Structure, Afferent Response Properties, and Cellular Physiology

Abstract

The first relays of the vertebrate electrosensory system arise from epidermal specializations with voltage-sensitive receptor cells that are tuned to the relevant frequencies of bioelectric fields. Despite diverse phylogenetic origins and adaptations to varying habitats, electroreceptor organs share a number of morphological and functional characteristics to facilitate the detection of low-intensity electric fields. Much of the current knowledge of physiological mechanisms underlying electrosensory transduction has been gleaned from in vivo electrophysiological recordings from primary electrosensory afferents or recordings of electrical impulses from the organs themselves. Recent advances in genetic and patch-clamp electrophysiological techniques have made detailed comparisons of the molecular mechanisms of transduction possible. These comparisons have the potential to shed light on convergent mechanisms of stimulus transduction and filtering among diverse species as well as broad themes of signal transduction relevant to other hair cell-based sensory systems.