[Sensitivity of animals to central nervous system stimulants in hypokinesia].

The experiments were carried out on 1150 non-inbred white male rats weighing 200+/-50 g. The animals were housed in small cages for 1, 5, 10, 15, 30, 45 and 60 days. Control rats remained normally active. The experimental and control animals were given a typical diet. On the above days the rats were injected intraperitoneally with central nervous stimulants--caffeine, phenamine and strychnine. Changes in the animal sensitivity to the stimulants were measured with respect to the alterating of LD16, LD50 and LD54 in test animals as compared with the controls and in regards to the emergence and duration of behavioural reactions: adynamics (caffeine), stereotype behavior (phenamine) and convulsions (strychnine). The greatest changes in the animal sensitivity were noted in response to phenamine. A significant increase in the sensitivity to caffeine was found on the 5, 15 and 45th experimental days and to strychnine only on the 5 and 45th days. Convulsions in response to strychnine were recorded in experimental animals earlier than in the controls and their duration was dependent on the doses injected. Adynamics in response to caffeine developed in experimental rats later than in the controls (on the 15th day) and its duration changed cyclically. Stereotype behavior in response to phenamine showed cyclic pattern and its duration in experimental rats was shorter than in the controls.