CORTICOSTERONE IN THE RANGE OF STRESS-INDUCED LEVELS POSSESSES REINFORCING PROPERTIES - IMPLICATIONS FOR SENSATION-SEEKING BEHAVIORS

In both humans and animals certain individuals seek stimuli or situati ons that are considered stressful and consequently avoided by others. A common feature of such situations is an activation of the hypothalam o-pituitary-adrenal axis leading to secretion of glucocorticoids. Sinc e glucocorticoids have euphoric effects in some individuals and have b een shown to potentiate the reinforcing properties of drugs of abuse i n animals, we hypothesized that corticosterone secretion during stress -like situations may have reinforcing effects and that a higher sensit ivity to the reinforcing effects of glucocorticoids might be a biologi cal basis of sensation seeking. In this report we show that (i) cortic osterone has reinforcing properties, as evidenced by the development o f intravenous self-administration, (ii) self-administration of cortico sterone is observed at plasma levels that are comparable to those indu ced by stress, and (iii) there are individual differences in corticost erone self-administration, which are related to individual reactivity to novelty and sensitivity to drugs of abuse, behavioral features akin to certain traits of high-sensation seekers. These findings provide i nsight into the physiological role of glucocorticoids and the biology of sensation seeking and may have clinical implications.