The effects of age and illumination on the dose-response curves for three stimulants.
The dose-response relationships for three stimulants have been explored. These drugs have been shown to differ in potency and, with successive doubling of doses, have been found to have dose-response curves of differing slopes. In addition, the relationship between dose and activity level was not the same for younger and older rats. The relationship between dosage of both d-amphetamine and methylphenidate and locomotor activity was not the same in the light and the dark. The latter finding suggests a difference between these two stimulants and the third stimulant studied, caffeine, whose effects where unaltered by ambient illumination level.
D000223:Adaptation, Psychological; D000375:Aging; D000818:Animals; D001143:Arousal / Q000187:drug effects; D002110:Caffeine / Q000008:administration & dosage / Q000494:pharmacology*; D003624:Darkness; D003913:Dextroamphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008027:Light; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains
D008774:Methylphenidate; D002110:Caffeine; D003913:Dextroamphetamine