sp0055">Pharmacological (CSA) and viral-mediated gene transfer (adeno-associated viral expression of short hairpin RNA [shRNA]) approaches were used to inhibit calcineurin activity systemically or selectively in the amygdala of the mouse brain to determine the role of calcineurin in behaviors related to anxiety and depression.
sp0060">Systemic inhibition of calcineurin activity with CsA or local downregulation of calcineurin levels in the amygdala using adeno-associated viral-delivered shRNAs targeting calcineurin B increased measures of anxiety-like behavior in the elevated plus maze, the light/dark box, and the open field test. A decrease in locomotor activity was also observed in mice treated systemically with CsA. In the forced swim model of depression-like behavior, both systemic CsA treatment and shRNA-mediated calcineurin blockade in the amygdala significantly increased immobility.
sp0065">Taken together, these data demonstrate that decreasing calcineurin activity in the amygdala increases anxiety-like behaviors and to some extent depression-like behaviors. These studies suggest that chronic administration of CsA to organ transplant patients could have significant effects on anxiety and mood and this should be recognized as a potential clinical consequence of treatment to prevent transplant rejection.