Age-Related Responsiveness of the Rat to Drugs Affecting the Central Nervous System

Abstract
Responses to sodium hexobarbital, chlorpromazine HCl, morphine SO4 and d-amphetamine SO4 were evaluated in 2.5-3 mo. old and 9-10 mo. old male rats. The control responses which were measured, body temperature, spontaneous motor activity and pain thresholds were not different in the 2 age groups studied. When the animals were challenged with the drugs a significantly higher responsiveness to the drugs occurred in the older animals.