Logo image
Intracellular Ca2+ and adaptation of voltage responses to light in Hermissenda photoreceptors
Journal article   Peer reviewed

Intracellular Ca2+ and adaptation of voltage responses to light in Hermissenda photoreceptors

I A Muzzio, A C Talk and L D Matzel
Neuroreport, Vol.9(7), pp.1625-1631
05/11/1998
DOI: 10.1097/00001756-199805110-00067
PMID: 9631477

View Online

Abstract

Fluorescent imaging of Ca2+ and intracellular recordings were used to assess Ca2+ increases and voltage responses during light presentations in Hermissenda B photoreceptors. Ca2+ levels increased and were sustained during a relatively long exposure to light. Repeated presentations of a brief light induced an elevation of intracellular Ca2+ that persisted throughout short interlight intervals, but which dissipated during long interlight intervals. In all instances, the magnitude of the intracellular Ca2+ signal was inversely related to the amplitude of the light-induced generator potential. Blocking of voltage-dependent Ca2+ channels did not significantly affect the magnitude of the Ca2+ signal, suggesting that the intracellular Ca2+ response arises primarily from release from intracellular stores. These results indicate that Ca2+ plays an important role in the modulation of the voltage responses to light, acting to suppress the response during repetitive or prolonged stimulation.
Adaptation, Ocular - physiology Animals Cadmium - pharmacology Calcium - metabolism Calcium Channel Blockers - pharmacology Calcium Channels - physiology Darkness Electric Stimulation Electrophysiology - methods In Vitro Techniques Light Mollusca Photic Stimulation Photoreceptor Cells, Invertebrate - drug effects Photoreceptor Cells, Invertebrate - physiology Reaction Time

Details

Metrics

Logo image