Dynamics of the light-induced current in Hermissenda

Although many of the biochemical reactions involved in phototransduction ha ve been characterized, the identity of the ligand of the light-induced curr ent is still unknown. The present study addresses the issue of which ligand activates the light-induced sodium current in Hermissenda by developing a model of the biochemical reactions involved in phototransduction, and exami ning the dynamics of the light-induced current in response to various ligan ds such as calcium and IP3. The results show that IP3, but not calcium, is a plausible ligand for the light-induced sodium current, and IP3 production is co-localized with the sodium channel. (C) 1999 Elsevier Science B.V. Al l rights reserved.