Figure 9. Strychnine Blocks OC Suppression in Mutant Ears.

(A) At 10 mg/kg, strychnine injection blocked OC-mediated DPOAE suppression in mutant mice, leaving only the slow OC-mediated enhancement seen in Chrna9 null mice [25].

(B) At a lower strychnine dose (3 mg/kg), the onset of suppression in the mutant mice becomes more rapid, closely resembling the wild-type response without strychnine (Figure 7). Arrowheads in (A) and (B) indicate the first point after shock-train onset for each genotype: data acquisition times are approximately 1/point.