Master of Science
Effective decision-making involves careful consideration of all potential positive and negative outcomes. Importantly, negative outcomes often occur later in time, leading to underestimation, or “discounting,” of these consequences. The Delayed Punishment Decision-making Task (DPDT) was developed to study sensitivity to delayed vs immediate punishment during cost/benefit decision-making in rats. Rats choose between two levers, one resulting in a small, single-pellet reward with no foot shock punishment, and the other resulting in a larger, three-pellet reward followed by a mild foot shock punishment. This punishment is preceded by a systematically increasing delay as the blocks progress (0, 4, 8, 12, 16 s). DPDT revealed that rats choose the punished option more as the delay in punishment increases, which is indicative of discounting of delayed punishment. Here, we examined the effects of systemic administration of catecholaminergic drugs on sensitivity to delayed punishment discounting in male and female adult rats. We found that acute cocaine did not affect choice of rewards with immediate punishment but caused a dose-dependent reduction in choice of delayed punishment. Interestingly, this effect was more prominent in females than males. Neither activation nor blockade of the D1 dopamine receptor affected decision-making. Finally, activation, but not blockade, of the D2 dopamine receptor eliminated the discounting of delayed punishment. Overall, these data demonstrate that dopamine transmission differently modulate sensitivity to delayed vs. immediate punishment.
Dissertation or thesis originally submitted to ProQuest
Embargoed until 2023-05-03
Minnes, Grace L., "Dopaminergic modulation of discounting of delayed punishment" (2022). Electronic Theses and Dissertations. 3183.