Figure 7.

Lesions of the IL cortex have no effect on affective behaviors in defeated mice previously housed in standard environments. The diagram depicting experimental groups and third study design is shown in a. Behavioral responses are measured in the elevated zero maze (EZM, b), light/dark box (L/D, c), tail-suspension test (TST, d), forced-swim test (FST, e), and social interaction task (SI, f–i). IL lesions made before or after SE housing had no effect on displays of anxiety or depressive-like behaviors. Groups exposed to SD, regardless of infusion type, showed significant increases in anxiety and spent significantly more time in the dark chamber of the light/dark box (c) compared with non-defeated groups. Defeated groups spent significantly more time immobile in the tail-suspension test (d) and forced-swim test (e) and spent significantly less time with the aggressor mice in the social interaction task (f, g) compared with non-defeated controls. IL lesions had no effect on behavior in non-defeated groups. In defeated groups, lesions made before or after SE had no effect on behavioral response to SD. ILinf, IL Infusion; ILx, IL lesion; Ms, mouse; Obj, object. Results are expressed as mean ± SEM(n = 8 per group). Two-way ANOVA followed by Bonferroni’s post hoc test. Bonferroni’s test: *p < 0.05.