Figure 6
Individual-level comparison of treatment and sex effects on noise-induced changes in synapse counts and wave-I amplitude. Female and male mice were pre-treated with ISRIB or vehicle and exposed to 97.8 dB SPL noise, or unexposed (control; N = 3 in each sex/treatment condition). ABR was performed at PNE21 and synapses quantified at PNE45. (A) Comparison between female (black) and male (red) mice reveal no significant sex difference in synapse counts or wave-I amplitudes in control (left), vehicle (middle), or ISRIB (right) conditions. (B) Female and male control (left) and noise + vehicle-treated (middle) mice had similar suprathreshold wave-I amplitudes, but noise + ISRIB-treated male mice had significantly higher wave-I amplitudes compared to female mice (right, p = 0.0036, 2-way ANOVA for sex and frequency, repeated on frequency). (C) Wave-I amplitude and synapse correlation plots are presented. Effect of sex on wave-I amplitude (controlling for paired synapse count) or on paired synapse count (controlling for wave-I amplitude) was analyzed by multiple linear regression, demonstrating no significant differences between male and female mice in control (left) and noise + vehicle (middle) conditions, but significant shift towards higher wave-I amplitude, accounting for synapse number, in male, compared to female, mice under noise + ISRIB conditions (p = 0.028). Data represent means ± s.e., with individual animals shown in shaded lines or dots.
