CRTC1 and mood disorder: We focused our investigations on the PFC and HIP, as these two regions are widely implicated in mood disorders and are known to have high levels of agmatine.43 Quantitative PCR analyses of Agmat mRNA levels found a significant (t=−3.31, degree of freedom (df)=9, P=0.013) 1.5-fold increase of Agmat mRNA in the HIP and a threefold increase (t=−6.72, df=8, P<0.001) in the PFC of male Crtc1−/− mice (Figure 1a).