Fig. 3.

Schematic depiction of pikachurin interaction with dystroglycan and dystrophin in the photoreceptor ribbon synapse, GPR 158/179 orphan receptor and mGluR6 in neurotransduction with retinal bipolar neurons in visual processing. 1. Photons are captured as part of the phototransductive process which 2. Activates the voltage gated CAV1.4 Ca2+ channel. 3. The influx of Ca2+ activates transport processes of Glu neurotransmitter within synaptic vesicles which merge with the membrane of the synaptic gap. 4. This results in the release of glutamate into the synaptic gap. 5. Glutamate is taken up by the mGluR6 metabromic glutamate receptor on bipolar neurons in the retina. 6. Transient receptor potential cation channel subfamily M member 1 (TRPM1) regulates neurotransduction in activated bipolar neurons as part of visual processing. ON-bipolar cell dendrites express a unique metabotropic glutamate receptor 6 (mGluR6). TRPM1 is a mGluR6-coupled cation channel in retinal ON-bipolar cells that regulates G protein receptor (GPCR) coupled signaling. TRPMI1 is the end-point of the mGluR6 signal transduction cascade in bipolar neurons in the retina.