Striatal dopamine and the temporal control of behavior

Abstract

Striatal dopamine strongly regulates how individuals use time to guide behavior. Dopamine acts on D1- and D2- dopamine receptors in the striatum. However, the relative role of these receptors in the temporal control of behavior is unclear. To assess this, we trained rats on a task in which they decided to start and stop a series of responses based on the passage of time and evaluated how blocking D1 or D2-dopamine receptors in the dorsomedial or dorsolateral striatum impacted performance. D2 blockade delayed the decision to start and stop responding in both regions, and this effect was larger in the dorsomedial striatum. By contrast, dorsomedial D1 blockade delayed stop times, without significantly delaying start times, whereas dorsolateral D1 blockade produced no detectable effects. These findings suggest that striatal dopamine may tune decision thresholds during timing tasks. Furthermore, our data indicate that the dorsomedial striatum plays a key role in temporal control, which may be useful for localizing neural circuits that mediate the temporal control of action.

Keywords: Decision making; Decision threshold; Dopamine; Interval timing; Striatum; Time perception.

Figure 1:

Cannula location. A) Nissl-stained coronal section showing cannula placement in the dorsomedial striatum (right hemisphere). B) Cannula placements (in green) from all rats in the dorsomedial striatum group (n = 10). C) Nissl-stained coronal section showing cannula placement in dorsolateral striatum (right hemisphere). D) Cannula placements for all rats in the dorsolateral striatum group (n = 11).

Figure 2:. D2 blockade affects start and stop times, and D1 blockade affects stop times in the dorsomedial striatum.

A and B show normalized probe trial response rate during infusion sessions in the dorsomedial and dorsolateral striatum, respectively. C and D show start and stop times obtained via single-trial analysis in the dorsomedial striatum (n = 10) and dorsolateral striatum (n = 11), respectively. Circles indicate individual subject medians; colored lines show mean ± standard error for each infusion type; and gray lines indicate significant differences (p < 0.05).