Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States; Iowa Neuroscience Institute, University of Iowa, Iowa City, United States; Pappajohn Biomedical Institute, University of Iowa, Iowa City, United States
Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States; Iowa Neuroscience Institute, University of Iowa, Iowa City, United States; Pappajohn Biomedical Institute, University of Iowa, Iowa City, United States
Ravi P Yadav
Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States
Brittany Williams
Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States; Iowa Neuroscience Institute, University of Iowa, Iowa City, United States; Pappajohn Biomedical Institute, University of Iowa, Iowa City, United States
Jussara Hagen
Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States; Iowa Neuroscience Institute, University of Iowa, Iowa City, United States; Pappajohn Biomedical Institute, University of Iowa, Iowa City, United States
Paul J Derr
Department of Neuroscience, University of Wisconsin-Madison, Madison, United States
Vasily Kerov
Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States; Iowa Neuroscience Institute, University of Iowa, Iowa City, United States
Luca Della Santina
Department of Ophthalmology, University of California, San Francisco, San Francisco, United States
Sheila A Baker
Iowa Neuroscience Institute, University of Iowa, Iowa City, United States; Department of Biochemistry, University of Iowa, Iowa City, United States; Department of Ophthalmology, Iowa City, United States
Nikolai Artemyev
Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States; Iowa Neuroscience Institute, University of Iowa, Iowa City, United States; Department of Ophthalmology, Iowa City, United States
Mrinalini Hoon
Department of Neuroscience, University of Wisconsin-Madison, Madison, United States; Department of Ophthalmology and Visual Science, University of Wisconsin-Madison, Madison, United States
Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States; Iowa Neuroscience Institute, University of Iowa, Iowa City, United States; Pappajohn Biomedical Institute, University of Iowa, Iowa City, United States
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.
