Functional significance of glycogen synthase kinase-3 regulation by serotonin

► 5-HT1A receptors regulate phosphorylation of GSK3 in the hippocampus. ► PI3K/Akt signaling pathway mediates regulation of GSK3 by 5-HT1A receptors. ► 5-HT1A receptor-induced inhibition of contextual fear learning is GSK3β-dependent. ► Fluoxetine regulates phosphorylation of GSK3 in the hippocampus. ► Regulation of GSK3 is an intermediate of fluoxetine's anti-immobility effect.