GAL and major depressive disorder: From the point of view of its behavioral effects on MDD, preclinical studies conducted in rodents have shown that in Flinders sensitive line rats, which are considered to represent a genetic model of depression [119], [125I]galanin binding sites are found to be increased in the dorsal raphe nucleus and that Gal (1–29) can activate in a differential way its receptors eliciting either depressant or antidepressant effects depending on which activated 5-HT receptor subtype is in dominance [120,121,122].