Dopamine and sodium appetite: antagonists suppress sham drinking of NaCl solutions in the rat.
Sodium (Na) ingestion in rats depleted of Na is a strong, motivated behavior that is enhanced further when depleted rats are sham drinking. Dopamine plays a critical role in motivation, including reward associated with consumption of palatable tastes. The present studies assessed the role of dopamine in real and sham drinking of NaCl solutions after Na depletion with the diuretic furosemide (10 mg/kg). Dopamine (D2) receptor antagonists were evaluated (Haloperidol [0.1 mg/kg] and raclopride [0.2 mg/kg]), for their effects on sham and real drinking of 0.3 M NaCl. Sham drinking was markedly reduced by both antagonists whereas real drinking was unaffected. These effects did not appear to be due to malaise or suppression of motor behavior because drug-treated animals were able to increase ingestion substantially when offered less concentrated NaCl (0.1 M). These results suggest that the positive motivating properties of NaCl stimulation in depleted, sham-drinking rats are mediated by central D2 receptors.
Roitman
M F
MF
Department of Psychology, University of Washington, Seattle 98195-1525, USA.
Schafe
G E
GE
Thiele
T E
TE
Bernstein
I L
IL
D000818:Animals; D001066:Appetite / Q000187:drug effects / Q000502:physiology*; D004298:Dopamine / Q000502:physiology*; D018492:Dopamine Antagonists / Q000494:pharmacology*; D004326:Drinking / Q000187:drug effects / Q000502:physiology; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D009042:Motivation; D020891:Raclopride; D051381:Rats; D012457:Salicylamides / Q000494:pharmacology; D012462:Saline Solution, Hypertonic / Q000008:administration & dosage*; D013649:Taste / Q000187:drug effects / Q000502:physiology; D014882:Water-Electrolyte Balance / Q000187:drug effects / Q000502:physiology*
D018492:Dopamine Antagonists; D012457:Salicylamides; D012462:Saline Solution, Hypertonic; D020891:Raclopride; D006220:Haloperidol; D004298:Dopamine