archives@tulane.edu / The current set of experiments aimed to explore mechanisms underlying sex differences in impulsive behavior in adult rats and sex differences in structures involved in impulse control. Preliminary studies demonstrated sex differences in adult impulsive action and prepubertal impulsive choice with males making more impulsive responses than females. In our studies, neither prepubertal nor adult gonadectomy, and subsequently a loss of gonadal hormone exposure, had any effect on a sex difference in impulsive action. Neonatal exposure of gonadal hormones in females led to a masculinization of impulsive responding in adulthood and eliminated an observed sex difference. This result demonstrates neonatal gonadal hormones to be an organizing mediator of an adult sex difference in impulsive action. No sex difference was seen in adult impulsive choice across hormone conditions. Analysis of myelin protein levels within the orbitofrontal cortex (OFC), a region important for inhibiting impulsive behavior, revealed adult females to exhibit greater levels of myelin basic protein (MBP) than males. This adult sex difference was revealed to be mediated by organizing effects of pubertal gonadal hormone exposure. Inactivation of indirect pathway projecting striatal neurons, neurons important for inhibition of motor output, via designer receptors exclusively activated by designer drug (DREADD) technology, led to a decrease in impulsive responding in adult males and females, eliminating an observed sex difference. Collectively, these results demonstrate for the first time periods of gonadal hormone driven organization of brain morphology and behavior with implications for sex differences in decision making and impulse control. / 1 / Jeffrey Scott Darling
| Identifer | oai:union.ndltd.org:TULANE/oai:http://digitallibrary.tulane.edu/:tulane_90193 |
| Date | January 2019 |
| Contributors | Darling, Jeffrey (author), Mostany, Riccardo (Thesis advisor), School of Science & Engineering Neuroscience (Degree granting institution) |
| Publisher | Tulane University |
| Source Sets | Tulane University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | electronic, pages: 176 |
| Rights | No embargo, Copyright is in accordance with U.S. Copyright law. |
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