Spontaneous and amphetamine induced head-shaking in infant rats.
A variable proportion of albino rats 6-11 days old exhibit spontaneous and infrequent rotatory head-shaking episodes. This motor pattern is slightly anticipated and significantly increased in occurrence and duration by the administration of D-amphetamine (5 mg/Kg), with a maximal effect of the drug on the 9th day. The rate of amphetamine induced rhythmic head oscillations increases with age from below 5 cps on the 5th day to about 9 cps on the 10th day. The results are discussed in relation to maturation of both the underlying catecholaminergic pathways, activated by D-amphetamine, and the stretch reflex systems of the head and neck muscles participating in the rhythmic activity. Emphasis is placed on the difference between head-shaking and stereotyped activity.
D000375:Aging; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology; D001519:Behavior / Q000502:physiology*; D003913:Dextroamphetamine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D051381:Rats / Q000254:growth & development / Q000502:physiology*; D013239:Stereotyped Behavior / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
D003913:Dextroamphetamine