Ovarian Hormones Regulate Dopamine Release and Adaptive Motivation in Female Rats

motivation;sex differences;ovarian hormones;dopamine;estradiol;progesterone;Psychology;Social Sciences;Psychology

Yoest, KatieBerridge, Kent C ;

University of Michigan

关键词: motivation;    sex differences;    ovarian hormones;    dopamine;    estradiol;    progesterone;    Psychology;    Social Sciences;    Psychology;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/145908/ktyoest_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Sex differences in motivated behaviors have evolved due to sex-specific adaptive pressures. Importantly, the neural circuitry underlying motivation is regulated by release of gonadal hormones in females but not in males. This likely allows for the coordination of motivated behaviors which changes in reproductive state in females, which increases the likelihood that females will engage in behaviors that are most likely to enhance their reproductive success. Here, I propose that these changes in levels of circulating ovarian hormones, which regulate dopamine signaling within striatal circuitry, act to direct adaptive choice and motivation for food vs sexual reward.In Chapter 2, I first establish that acute treatment with estradiol benzoate enhances the effect of cocaine on phasic dopamine release within the nucleus accumbens of in females, but not males. I extend these findings to demonstrate the effects of estradiol seen here are regulated by activation of the selective estradiol receptor (ER) subtype, ERbeta. This work further clarifies the role of estradiol in regulating dopamine release but does not indicate the behavioral significance of ovarian hormones acting within this circuitry. Accordingly, I next sought to determine whether administration of estradiol benzoate and progesterone in a regimen that induces sexual receptivity and increases sexual motivation could also reduce motivation for food. I found that ovarian hormones do attenuate motivated responding for a palatable food reward, but only after administration of both estradiol benzoate and progesterone, indicating the effects of ovarian hormones on motivation for food are dissociable from their effects on consummatory feeding behavior and drug-induced dopamine release. In Chapter 4, I then tested whether ovarian hormones act to increase motivation for sex but decrease motivation for food in order to facilitate adaptive choice when females are sexually receptive. I found that administration of estradiol benzoate and progesterone not only decreased motivation for food and enhanced motivation for a mate when both rewards were available, but also biased a female’s choice for food vs access to a sexually experienced male conspecific. Taken together, these findings propose a potential explanation for why dopaminergic circuitry underlying motivated behaviors is responsive to ovarian hormones, providing an adaptive interpretation of a mechanism that is most commonly investigated within the context of maladaptive and disordered behaviors.