Microstructural analysis of the involvement of beta-receptors in amphetamine anorexia.
Rats were trained to take food by pushing the door of the pellet dispenser in an operant chamber. Log survivor analysis of the inter-response time frequency distribution was used to determine whether or not an animal was eating, at any time during a thirty minute session. This information was used to compute eating time, eating rate, and the mean length of bouts of eating and gaps between eating bouts. Video-recordings confirmed that the method discriminated eating from not eating with an accuracy of approximately ninety percent. Amphetamine (0.5 mg/kg) significantly reduced total food intake and eating time, and increased gap length; propranolol (5 mg/kg) significantly increased eating time and bout length. Following propranolol pretreatment, amphetamine significantly reduced eating time and bout length but also significantly increased eating rate; as a result there was no significant decrease in total food intake. The possible mediation of these effects by beta-adrenergic and dopaminergic systems is discussed.
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001921:Brain / Q000187:drug effects*; D003216:Conditioning, Operant / Q000187:drug effects; D004435:Eating / Q000187:drug effects*; D008297:Male; D009115:Muridae; D011433:Propranolol / Q000494:pharmacology; D011941:Receptors, Adrenergic / Q000187:drug effects*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*
D011941:Receptors, Adrenergic; D011943:Receptors, Adrenergic, beta; D011433:Propranolol; D000661:Amphetamine