Calcium-activated chloride channels in the retina

Abstract

This review examines the function of calcium-activated chloride currents (I(Cl(Ca))) in the retina with an emphasis on their physiological role in photoreceptors. Although found in a variety of neurons and glial cells of the retina, I(Cl(Ca)) has been most prominently studied in cones, where it activates in response to depolarization-evoked Ca(2+) influx. The slow and complex gating kinetics of the chloride current have been considered to reflect the changing submembrane concentration of intracellular calcium. It is likely that the role of I(Cl(Ca)) is to stabilize the membrane potential of cones during synaptic activity and presynaptic Ca channel modulation. Several candidates in the molecular identification of the channel have been put forward but the issue remains unresolved.

Multiple effects of anthracene-9-carboxylic acid on the TMEM16B/anoctamin2 calcium-activated chloride channel

“…Later they have been observed in diverse tissues including exocrine gland cells, neurons, heart, skeletal and smooth muscle [3][4][5][6][7][8][9][10][11][12].…”

Interactions between permeation and gating in the TMEM16B/anoctamin2 calcium-activated chloride channel

“…However, several studies on many ion channels have described interactions between permeation and gating, suggesting that these two processes are not always independent (Hille, 2001). Ca 2+ -activated Cl  channels (CaCCs) play important physiological functions, including regulation of cell excitability, fluid secretion, and smooth muscle contraction and block of polyspermy in some oocytes (Frings et al, 2000;Hartzell et al, 2005;Leblanc et al, 2005;Petersen, 2005;Wray et al, 2005;Lalonde et al, 2008;Duran et al, 2010;Berg et al, 2012;Huang et al, 2012a). Evidence that anions modify gating of endogenous CaCCs was reported in several cell types.…”

International Union of Basic and Clinical Pharmacology. LXXXV: Calcium-Activated Chloride Channels

“…CaCCs were also recorded in single cilia of olfactory receptor neurons (Kleene and Gesteland, 1991), photoreceptors in retina (Maricq and Korenbrot, 1988;Lalonde et al, 2008), and sensory neurons in mouse vomeronasal organ (Yang and Delay, 2010). Recent studies indicated that TMEM16B seems to be the CaCC expressed in the cilia olfactory sensory neurons and presynaptic terminals of retinal photoreceptors (Stephan et al, 2009;Hengl et al, 2010;Rasche et al, 2010).…”