Long-term Isolation in Rats reduces Morphine Response

• DOI: 10.1038/228469a0
• Publication Date: 2005-08-01T18:51:05Z
• Authors: D. M. KATZ; H. STEINBERG
• Keywords: 0301 basic medicine; 03 medical and health sciences; Morphine; Social Isolation; Depression, Chemical; Animals; Motor Activity; Rats

RECENTLY, interest has increased in the effects of previous home environments on reactions to drugs (for example, ref. 1) and experiments have been done on various species. Long-term isolation is known to induce aggressive behaviour and biochemical changes in mice2, and it also disrupts behavioural and physiological reactions in rats3,4. Isolation in both species increases their sensitivity to toxic effects of some stimulant drugs5,6, but shortens barbiturate sleeping times in mice7 and rats8, and reduces the stimulant effects of amphetamine-barbiturate mixtures on the activity of rats in a Y-maze (Clarke, Rushton and H. S., to be published). It seemed important to study the effects of long-term isolation on some responses by rats to morphine.