Cholinergic involvement in lateral hypothalamic rewarding brain stimulation.
Rats were implanted with stimulating electrodes in the lateral hypothalamus, and cannulae for chemical injections in the ventral tegmentum. Injections of atropine, a muscarinic antagonist, increased thresholds for self-stimulation in a dose-dependent fashion, without slowing bar pressing rates. Thresholds increased less for a self-stimulation site contralateral to the atropine injection. In a conditioned place preference test, the rats preferred compartments in which they received carbachol, a cholinergic agonist. Muscarinic receptors in ventral tegmentum therefore seem critical for medial forebrain bundle (MFB) reward. The possible cholinergic cells of origin are discussed.
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001931:Brain Mapping; D002217:Carbachol / Q000494:pharmacology; D002799:Cholinergic Fibers / Q000502:physiology; D007026:Hypothalamic Area, Lateral / Q000502:physiology*; D008297:Male; D008474:Medial Forebrain Bundle / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology*; D051381:Rats; D011976:Receptors, Muscarinic / Q000502:physiology; D012201:Reward; D012653:Self Stimulation / Q000502:physiology*
D011976:Receptors, Muscarinic; D001285:Atropine; D002217:Carbachol