Mesolimbic regions, including the nucleus accumbens (NAc) mediate the motivational properties of food, sex, and drug rewards, as well as cues that are paired with them. It is well established that ovarian hormones influence motivation (Yoest et al., 2014) and potently regulate NAc function and plasticity (Cyr et al., 2001; Le Saux et al., 2006; Peterson et al., 2015). In addition, glutamatergic transmission in the NAc is essential for the initiation of motivated behaviors. The regulation of NAc glutamatergic synaptic plasticity by ovarian hormones is proposed to underlie motivational responses to food and drug rewards (Becker and Hu, 2008; Sinclair et al., 2017). However, the mechanisms underlying the modulatory role of ovarian hormones on NAc function and motivation are poorly understood. Thus, the goal of the proposed studies is to combine behavioral, biochemical and electrophysiological approaches to understand how ovarian hormones influence motivation and NAc function. These studies will not only provide a better understanding of the role of ovarian hormones in motivation and NAc function, but they will also provide training and preparation for my independent research career.
Food intake and feeding behaviors are regulated by the reproductive cycle. It has been shown that females have greater risk of suffering from obesity and eating disorders. In addition, females show enhanced behavioral responses to the rewarding properties of food and drugs of abuse compared to males. Furthermore, hormonal changes across the cycle can affect female responses to food, sex and addictive drugs. The goal of the proposed studies is to determine the role of the reproductive cycle and ovarian hormones in modulating cue-triggered motivation for food and the underlying neural mechanisms.
