RT Journal Article
SR Electronic
T1 Dopamine release and its control over early Pavlovian learning differs between the NAc core and medial NAc shell
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.07.29.227876
DO 10.1101/2020.07.29.227876
A1 Claire E. Stelly
A1 Kasey S. Girven
A1 Merridee J. Lefner
A1 Kaitlyn M. Fonzi
A1 Matthew J. Wanat
YR 2020
UL http://biorxiv.org/content/early/2020/10/20/2020.07.29.227876.abstract
AB Dopamine neurons respond to cues to reflect the value of associated outcomes. These cue-evoked dopamine responses can encode the relative rate of reward in rats with extensive Pavlovian training. Specifically, a cue that always follows the previous reward by a short delay (high reward rate) evokes a larger dopamine response in the nucleus accumbens (NAc) core relative to a distinct cue that always follows the prior reward by a long delay (low reward rate). However, it was unclear if these reward rate dopamine signals are evident during early Pavlovian training sessions and across NAc subregions. To address this, we performed fast-scan cyclic voltammetry recordings of dopamine levels to track the pattern of cue and reward-evoked dopamine signals in the NAc core and medial NAc shell. We identified regional differences in the progression of cue-evoked dopamine signals. However, reward rate encoding was not evident in either the NAc core or NAc shell during early training sessions. Pharmacological experiments found that dopamine-sensitive conditioned responding emerged in the NAc core before the NAc shell. Together, these findings illustrate regional differences in NAc dopamine release and its control over behavior during early Pavlovian learning.Competing Interest StatementThe authors have declared no competing interest.