Figure 5. Postsynaptic remodeling and ectopic ribbons in mice with altered Ca_v1.4 function. Double-label immunofluorescence of PKCα (green) and RIBEYE (red) in retina from WT, Ca_v1.4 KO, CaBP4 KO, or Ca_v1.4_I756T mice (P8-adult). In WT retina, bipolar dendrites labeled with PKCα antibodies ramify in the OPL where they form synapses with rod spherules. In Ca_v1.4 KO mice, bipolar dendrites (arrows) start extending into the outer nuclear layer (ONL) at P11, and ectopic ribbons labeled by RIBEYE antibodies are evident (arrowheads). Postsynaptic remodeling emerges later in CaBP4 KO and Ca_v1.4_I756T mice (~P13), and is less severe in adulthood (2-mo old) compared with WT mice. Scale bars: 2 μm. Results shown are representative of at least 3 independent experiments.