Biology subjects

Griffin, N. K.

Publications and source records attributed to Griffin, N. K..

5 recordsLinked to original sources

bioRxiv2026

Dopamine projections to the basolateral amygdala enable reward prediction

Reward predictions are critical to both adaptive learning and decision making. Such predictions are supported by environmental cues that signal the availability and identity of rewarding events. Here we used fiber photometry, cell-type and pathway-specific optogenetic inhibition, Pavlovian cue-reward conditioning, and decision-making tests in male and female rats to reveal that ventral tegmental area dopamine (VTADA) projections to the basolateral amygdala (BLA) support cue-reward predictions. Reward-predictive cues trigger dopamine release in the BLA that encodes the value of the predicted reward. This cue-evoked VTADA[->]BLA activity mediates the ability of cue-reward predictions to bias action selection and adapt cue-response decisions based on the current value of the predicted reward. Cue-evoked VTADA[->]BLA activity also mediates the constraining influence of cue-reward predictions on new learning. Thus, cue-evoked BLA dopamine supports the reward predictions that both enable adaptive decision making and constrain learning.

neuroscience↗

bioRxiv2025

Dopamine supports reward prediction to constrain reward seeking

Reward predictions not only promote reward pursuit, they also shape how reward is pursed. Such predictions are supported by environmental cues that signal reward availability and probability. Such cues trigger dopamine release in the nucleus accumbens core (NAc). Thus, here we used dopamine sensor fiber photometry, cell-type and pathway-specific optogenetic inhibition, Pavlovian cue-reward conditioning, and test of cue-induced reward-pursuit strategy in male and female rats, to ask whether cue-evoked phasic dopamine release is shaped by reward prediction to support reward pursuit. We found that cue-evoked NAc core dopamine is positively shaped by reward prediction and inversely relates to and predicts instrumental reward seeking. Cues that predicted imminent reward with high probability triggered a large NAc dopamine response and this was associated checking for the expected reward in the delivery location, rather than instrumental reward seeking. Cues that predicted reward with low probability elicited less dopamine and this was associated with a bias towards seeking, rather than check for reward. Correspondingly, inhibition of cue-evoked NAc dopamine increased instrumental reward-seeking and decreased reward-checking behavior. Thus, transient, cue-evoked NAc core dopamine release supports reward prediction to shape reward-pursuit strategy. SIGNIFICANCE STATEMENTCues that signal reward availability can cause us to pursue reward. To ensure this is adaptive, we use the predictions these cues enable to help us decide how to pursue reward. When reward prediction is low, well seek out new reward opportunities. When it is high, well exploit the expected reward by checking for it in its usual location. Here we discovered that transient, cue-evoked nucleus accumbens dopamine fluctuations support reward predictions to shape how reward is pursued. The data show that dopamine can actually constrain reward seeking and promoting reward checking when reward is predicted strongly and imminently. These results provide new information on how dopamine shapes behavior in the moment and help understand the link between motivational and dopamine disruptions in psychiatric conditions such as addictions and depression.

neuroscience↗

bioRxiv2025

Striatal cell-type specific stability and reorganization underlying agency and habit

Goal-directed behavior is guided by learned action-outcome associations, allowing actions to adapt when outcomes change. With repetition, behavioral control shifts toward habit, enabling more automatic action execution, but reducing flexibility to outcome changes. Here, we used longitudinal, cellular-resolution calcium imaging, chemogenetics, instrumental conditioning, and the outcome devaluation test to ask how dorsomedial striatum D1+ and D2/A2A+ neurons contribute to the formation of goal-directed behavior and habit. DMS D1+ neurons stably encode instrumental actions, carry information about behavioral engagement and organization, and develop and maintain action-reward representational similarity and conjunctive activation with learning. Correspondingly, these neurons are critical for action-outcome learning and goal-directed decision making. In contrast, one ensemble of DMS A2A+ neurons transiently encodes actions during early action-outcome learning and another slowly starts to encode actions as habits form. Similarly, DMS A2A+ neurons transiently mediate action-outcome learning and become dispensable for goal-directed decision making. Thus, action-outcome associations are learned through DMS D1+ and A2A+ neuronal activity but only DMS D1+ neurons maintain support of adaptive, goal-directed decision making. Habit formation is associated with reorganization of A2A+ neuronal encoding. These data reveal a cell-type-specific dissociation between stable v. reorganizing striatal action representations paralleled by persistent v. transient contributions to goal-directed control.

neuroscience↗

bioRxiv2022

Dopamine projections to the basolateral amygdala drive the encoding of identity-specific reward memories

To make adaptive decisions, we build an internal model of the associative relationships in an environment and use it to make predictions and inferences about specific available outcomes. Detailed, identity-specific cue-reward memories are a core feature of such cognitive maps. Here we used fiber photometry, cell-type and pathway-specific optogenetic manipulation, Pavlovian cue-reward conditioning, and decision-making tests in male and female rats, to reveal that ventral tegmental area dopamine (VTADA) projections to the basolateral amygdala (BLA) drive the encoding of identity-specific cue-reward memories. Dopamine is released in the BLA during cue-reward pairing and VTADA[->]BLA activity is necessary and sufficient to link the identifying features of a reward to a predictive cue, but does not assign general incentive properties to the cue or mediate reinforcement. These data reveal a dopaminergic pathway for the learning that supports adaptive decision making and help explain how VTADA neurons achieve their emerging multifaceted role in learning.

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bioRxiv2018

Measuring narrative engagement: The heart tells the story

Stories play a fundamental role in human culture. They provide a mechanism for sharing cultural identity, imparting knowledge, revealing beliefs, reinforcing social bonds and providing entertainment that is central to all human societies. Here we investigated the extent to which the delivery medium of a story (audio or visual) affected conscious and subconscious engagement with the narrative. Although participants self-reported greater involvement for watching video relative to listening to auditory scenes, stronger physiological responses were recorded for auditory stories. Sensors placed at their wrists showed higher and more variable heart rates, greater electrodermal activity, and even higher body temperatures. We interpret these findings as physiological evidence that the stories were more cognitively and emotionally engaging when presented in an auditory format. This may be because listening to a story, rather than watching a video, is a more active process of co-creation, and that this imaginative process in the listeners mind is detectable on the skin at their wrist.

neuroscience↗