[Psychobiological study of habituation to stress--observation of behavioral and neurochemical changes].
The effect of acute and chronic stress on escape behavior, brain norepinephrine (NE) concentration and beta-receptor binding was examined, and the mechanism of adaptation to chronic stress was discussed in terms of both behavioral and neurochemical standpoint. The rats were divided into an acute stress group (AS), chronic stress group (CS) and control group (C). The rats of AS experienced a single stress session. The rats of CS received 5 separate sessions. The rats of each group were examined by escape test, or killed for the purpose of measurement of beta-receptor binding and NE concentration 30 min after the final shock. The latency of escape test of AS was significantly greater than that of C. On the other hand, the latency of CS, and cortex beta-receptor binding of CS was significantly lower than that of C. However, beta-receptor binding of hypothalamus of AS and CS was not different from that of C. These results indicate that adaptation to chronic stress occurs with respect to escape behavior, and its neurochemical background relates with the acceleration of NE turnover and down regulation of beta-receptor sensitivity of cerebral cortex.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D004082:Dihydroalprenolol / Q000378:metabolism; D004924:Escape Reaction; D006185:Habituation, Psychophysiologic; D006801:Humans; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D013312:Stress, Physiological / Q000378:metabolism*; D013315:Stress, Psychological
D011943:Receptors, Adrenergic, beta; D004082:Dihydroalprenolol; D009638:Norepinephrine