FIGURE 7

Facial branchiomotor neurons are less active in olt mutants. (A,B) Dorsal views, with anterior to the left, of the hindbrains of 7 dpf Tg(zCREST1:GCaMP6s);TgzCREST1:mRFP larvae showing GCaMP fluorescence intensities. (A) In a wildtype larva, fluorescence can be seen in the FBM neurons (arrowheads) in r6, as well as the trigeminal motor neurons (nV) in r2. (B) In an olt mutant, fluorescence is evident in the nV neurons in r2 and in the FBM neurons (arrowheads) that have failed to migrate out of r4. (C) Overlay of GCaMP6s ΔF/F traces for a representative wildtype sibling (blue) and an olt mutant (orange) showing fewer Ca²⁺ events (asterisks) in the mutant. Amplitudes of the Ca²⁺ events were not affected. (D) The frequency of Ca²⁺ events in FBM neurons was significantly lower in olt mutants compared to wildtype siblings. The Ca²⁺ event frequency for trigeminal motor (nV) neurons was not affected in mutants. Data pooled from 6 experiments (number of larvae in parenthesis). The two-tailed student t-test was performed to test for significance, *p < 0.01.