ANXIETY-LIKE AND DEPRESSION-LIKE BEHAVIOR IN MAUDSLEY REACTIVE (MR) AND NONREACTIVE (NMRA) RATS

1. Female MR (''anxious'') and MNRA (''non-anxious'') Maudsley rats we re tested in the CSD behavioral conflict paradigm (anxiety-like measur e) and also in the FST paradigm (depression-like measure). 2. As expec ted, MNRA rats accepted significantly more shocks in the CSD paradigm than did MR rats (i.e., MNRA rats were less ''anxious''); MNRA rats al so exhibited significantly less immobility in the FST procedure (i.e., MNRA rats were less easily made ''depressed''). 3. When the data were pooled across the two strains, there was a significant correlation be tween CSD and FST behavioral scores; however, there was no significant correlation between these measures when the data from the two strains were evaluated separately. Multiple regression (independent variables of rat strain and CSD score, dependent variable of FST score) reveale d a significant effect of rat strain, but not CSD score, on FST behavi or. 4. The relationship of these findings to the apparent relationship between anxiety and depression in humans is discussed.