Cyclic AMP and central noradrenaline receptors: failure to activate diencephalic adrenergic feeding pathways

Intracranial injection of graded doses of dibutyryl 3',5'-cyclic adenosine monophosphoric acid (cAMP) at sites in the accumbens/stria terminalis nuclei of satiated rats elicited behavioural arousal and occasional convulsive episodes at higher doses, but failed to affect food consumption even in sites where injection of noradrenaline (65 nmol) consistently elicited increased feeding. Intracranial aminophylline (550 nmol) or dopamine (65 nmol) were also without effect on food consumption. This result does not support recent suggestions that cAMP serves as the second messenger in central noradrenergic motivational pathways.