Author(s): Maddox JW, Randall KL, Yadav RP, Williams B, Hagen J, Derr PJ, Kerov V, Della Santina L, Baker SA, Artemyev N, Hoon M, Lee A. A dual role for Ca(v)1.4 Ca(2+) channels in the molecular and structural organization of the rod photoreceptor synapse. Elife. 2020 Sep 17;9. pii: e62184. doi: 10.7554/eLife.62184. [Epub ahead of print] PMID 32940604
Journal: E Life, Volume 9, Sep 2020
Synapses are fundamental information processing units that rely on voltage-gated Ca2+ (Cav) channels to trigger Ca2+-dependent neurotransmitter release. Cav channels also play Ca2+-independent roles in other biological contexts, but whether they do so in axon terminals is unknown. Here, we addressed this unknown with respect to the requirement for Cav1.4 L-type channels for the formation of rod photoreceptor synapses in the retina. Using a mouse strain expressing a non-conducting mutant form of Cav1.4, we report that the Cav1.4 protein, but not its Ca2+ conductance, is required for the molecular assembly of rod synapses; however, Cav1.4 Ca2+ signals are needed for the appropriate recruitment of postsynaptic partners. Our results support a model in which presynaptic Cav channels serve both as organizers of synaptic building blocks and as sources of Ca2+ ions in building the first synapse of the visual pathway and perhaps more broadly in the nervous system.