Given the associations between Per3 and stress- and alcohol-related traits, we evaluated the expression of Per3 under five different conditions: (1) RSE, (2) RSS, (3) NOS, (4) NOE and (5) NON. Four-way nested ANOVA revealed significant effects of strain and an interaction between stress and ethanol on Per3 expression (P<0.05; Figure 6a). Post hoc analysis showed significantly higher Per3 expression (P<0.05) in the ethanol and the stress with ethanol groups (NOE and RSE) compared with the naive (NON) and saline controls (NOS). However, there was no significant effect of restraint alone—that is, no difference between RSS and NON/NOS groups on Per3 expression (P<0.08) (Figure 6b).
