The Dzirasa lab uses chronic social defeat stress to create an ecologically relevant model for depression in mouse models. The model results in the expression of two distinct phenotypes, resilient and susceptible, similar to the phenotypes seen in human patients who have different responses to stressful events.The aim of my project was to correlate the behavioral changes associated with chronic anti-depressant treatment of socially defeated mice with biochemical changes of the level of phosphorylation of the protein MeCP2 in the lateral habenula. Previous work by the West lab studying the methyl DNA-binding protein MeCP2 has found that MeCP2 is phosphorylated by monoamine neurotransmitters. Increased levels of MeCP2 phosphorylation in the lateral habenula were found with chronic treatment of imipramine, indicating that MeCP2 may have a role in the brain’s biochemical response to chronic anti-depressant treatment. In order to correlate MeCP2 phosphorylation during anti-depressant treatment with behavioral recovery of a prosocial phenotype in socially defeated mice, mice will undergo two rounds of behavioral tests before and after imipramine treatment and then will be tested for levels of MeCP2 phosphorylation. If phosphorylation is correlated with behavioral recovery, susceptible mice that display resilient behavior after imipramine treatment will also have increased levels of MeCP2 phosphorylation in the lateral habenula.