Fig. 5.

Decreasing CaMKII α-hM4Di-positive DCN cell activity during noise exposure does not prevent tinnitus-like behavior and abolishes hM4Di-dependent recovery. A Schematic timeline highlighting GPIAS recordings before and after noise exposure. B Schematic outline of Startle and Startle-gap protocols. C Representative GPIAS response. D, E Group results for startle suppression of all frequencies tested before (blue) and after (dark red) noise exposure in the presence of CNO for hM4Di (D) and eYFP (E) injected mice. F, G Left, quantification of most affected frequency of each animal. Right, Inhibition of CaMKII α-hM4Di-positive DCN cells during noise exposure did not prevent a decrease in the startle suppression, indicating tinnitus, and also the second CNO injection before GPIAS recording (in mice receiving CNO 30 min before the noise exposure) did not recover startle suppression (F; p = 0.404). The eYFP injected group showed tinnitus-like behavior after noise exposure with CNO and did not recover the startle suppression after CNO injection upon testing GPIAS (G; p = 0.176). n = 6 and 6 for NE+CNO hM4Di+ and NE+CNO eYFP; *p <0.05