Adrenal function response to chronic stress in rats with anterodorsal thalami nuclei lesions.

The effects of chronic stress (forced immobilization, 15 min/day during 12 days), on the plasma corticosterone and the adrenal catecholamines response in rats with anterodorsal thalami nuclei (ADTN) lesions were studied. In sham lesioned rats, chronic stress produced a significant increase in plasma corticosterone (C), as compared to unstressed animals (p < 0.05). The adrenal C was, however, similar in both groups. There were no differences in plasma C values between unstressed and stressed lesioned rats. The adrenal C content, was significantly lower (P < 0.005) in stressed lesioned rats when compared with unstressed lesioned animals. Adrenal norepinephrine (NE) values, in sham lesioned rats after forced immobilization, were significantly below those found in unstressed sham lesioned ones (P < 0.05). There were no changes in adrenal epinephrine (E) response after forced immobilization. In lesioned rats, NE response to chronic stress showed the opposite pattern to that in sham lesioned ones; the adrenal glands of these animals showed a significant increase in NE content as compared to unstressed lesioned rats (P < 0.01). Similar alterations in the adrenal E concentration were found, post stress values were significantly higher (P < 0.01).