Studies of the Relationship between Catalepsy and Anxiety, Aggression, and Depression-Like Behavior Using Congenic Mouse Strains

Abstract

Catalepsy is a passive-defensive freezing reaction produced in response to threatening stimuli which in exaggerated form constitutes a syndrome of impaired brain function. In mice, the major gene determining susceptibility to catalepsy has been located in the distal 55–75 cM fragment on chromosome 13. Two congenic strains were constructed: AKR.CBA-D13Mit76 and AKR.CBA-D13Mit78, which carry two fragments, i.e., 55–71 and 71–75 cM of chromosome 13, respectively, which were transferred from cataleptic strain CBA to the genome of the non-cataleptic AKR strain. Half of AKR.CBA-D13Mit76 mice were found to show pronounced catalepsy, comparable to that of animals of the donor strain CBA. Decreases in investigative behavior in the open field test were also seen, along with decreases in intermale aggression, as compared with AKR mice, while there were no differences in the forced swimming test. AKR.CBA-D13Mit78 mice showed no differences in comparison with the parent AKR strain in tests for catalepsy, in the open field test, the forced swimming test, or tests for aggression.