| Abstract: | The effects of controllable and uncontrollable stress on the receptor binding of dexamethasone in the hypophysis and hippocampus were studied in KHA and KLA rats, lines selected for the ability to development of active escape. Presentation of the controllable stimulus led to a significant reduction in receptor binding of dexamethasone in the hippocampus with significant changes in the plasma corticosterone concentration and receptor binding in the hypophysis. KLA rats were sensitive both to the controllable and the uncontrollable stresses, with increases in plasma corticosterone and receptor binding of dexamethasone in the hypophysis. It is concluded that receptor binding of dexamethasone in the hippocampus and hypophysis depend not only on the behavioral strategy of the animal, but also on the possibility of controlling the situation. Laboratory of Endocrine System Physiology and Pathology, I. P. Pavlov Institute of Physiology, Russian Academy of Sciences, 199034 St. Petersburg. Translated from Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 82, No. 2, pp. 50–54, February, 1996. |
