A non-conducting role of the Ca_v1.4 Ca²⁺ channel drives homeostatic plasticity at the cone photoreceptor synapse.

ABSTRACT: In congenital stationary night blindness type 2 (CSNB2)-a disorder involving the Ca_v1.4 (L-type) Ca²⁺ channel-visual impairment is mild considering that Ca_v1.4 mediates synaptic release from rod and cone photoreceptors. Here, we addressed this conundrum using a Ca_v1.4 knockout (KO) mouse and a knock-in (G369i KI) mouse expressing a non-conducting Ca_v1.4. Surprisingly, Ca_v3 (T-type) Ca²⁺ currents were detected in cones of G369i KI mice and Ca_v1.4 KO mice but not in cones of wild-type mouse, ground squirrel, and macaque retina. Whereas Ca_v1.4 KO mice are blind, G369i KI mice exhibit normal photopic (i.e., cone-mediated) visual behavior. Cone synapses, which fail to form in Ca_v1.4 KO

SUBMITTER: Maddox JW 

PROVIDER: S-EPMC10723350 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature