Dysregulation of Striatal Dopamine Signaling by Amphetamine Inhibits Feeding by Hungry Mice

Abstract

AbstractAmphetamine (AMPH) releases monoamines, transiently stimulates locomotion, and inhibits feeding. Using a genetic approach, we show that mice lacking dopamine (DA-deficient, or DD, mice) are resistant to the hypophagic effects of a moderate dose of AMPH (2 μg/g) but manifest normal AMPH-induced hypophagia after restoration of DA signaling in the caudate putamen by viral gene therapy. By contrast, AMPH-induced hypophagia in response to the same dose of AMPH is not blunted in mice lacking the ability to make norepinephrine and epinephrine (Dbh−/−), dopamine D2 receptors (D2r−/−), dopamine D1 receptors (D1r−/−), serotonin 2C receptors (Htr2c−/Y), neuropeptide Y (Npy−/−), and in mice with compromised melanocortin signaling (Ay). We suggest that, at this moderate dose of AMPH, dysregulation of striatal DA is the primary cause of AMPH-induced hypophagia and that regulated striatal dopaminergic signaling may be necessary for normal feeding behaviors