Skip to main content
. 2023 Mar 31;14:1125948. doi: 10.3389/fimmu.2023.1125948

Figure 7.

Figure 7

SB225002 reduces cisplatin-induced loss of synaptic function and ribbon synapses. ABR Wave 1 amplitudes (A) and latencies (B) were collected from all treatment groups at 60, 70, 80, 90, dB SPL (32 KHz). (A) Cisplatin significantly decreases supra-threshold amplitudes while SB225002 (1.4 nmoles/ear) protected against cisplatin effects (P<0.0001 between vehicle cisplatin and SB225002+cisplatin, F(3,86)=74.39 and DF=86). Data represent mean ± SEM of four rats. Statistical analyses were performed using two-way analysis of variance (ANOVA). (B) Cisplatin significantly increased supra-threshold Wave 1 latencies which were reduced by SB225002 (P<0.0001 between vehicle cisplatin and SB225002+cisplatin, F(3,88)=43.43 and DF= 88). Statistical analyses were performed using two-way analysis of variance (ANOVA). (C) Male Wistar rats were pretreated with vehicle or SB225002 30 min later, cochleae were collected and subjected to whole-mount dissection to isolate basal, middle and apex turns. turns sections were stained with hair cell marker, myosin VIIa (blue), CtBP2 pre-synaptic marker (red) and GluR2 post-synaptic marker (green). Representative whole-mount images from turns showed that cisplatin reduced the number of ribbon synapse per IHC which was blunted by trans-tympanic SB225002. Orphan synapses represent staining by either GluR2 or CtBP2 alone which were not paired (indicated by white arrows). (D) The number of synaptic ribbons per IHC in the basal turn was reduced by cisplatin, but this response was attenuated by SB225002 (P<0.0001 between vehicle cisplatin and SB225002+cisplatin, F(3,28)=138 and DF=31). (E) Cisplatin significantly induce the number of orphan synapses per IHC which was protected by SB225002 (P<0.0001 between vehicle cisplatin and SB225002+cisplatin, F(3,28)=47.8 and D.F equals 31). Asterisks, (*) indicates significant difference from vehicle group, while (**) indicate significant difference form cisplatin group. Statistical analyses among groups were tested using one-way analysis of variance (ANOVA). Data indicates mean ± SEM.