Whole cell recordings from mPFC cells showing percentage of cells that show a response to the bath perfused drug. A smaller proportion of Hetero-KO mPFC pyramidal cells responds to 5-CT compared to controls (Control: 9/11;Hetero-KO: 3/10)(Fisher’s: p<0.05; n=10–11/group). No changes were observed in the percentage of non-pyramidal cells. (Control: 3/7;Hetero-KO: 4/9)(Fisher’s: p=1.0)(n=7–9/group). All pyramidal cells respond robustly to Baclofen (Control: 4/4;Hetero-KO: 4/4)(Fisher’s: p=1.0; n=4/group).