Reward-Predictive Neural Activities in Striatal Striosome Compartments

Area of Science:

• Neuroscience
• Reward Prediction
• Striatal Function

Background:

• The striatum is crucial for reward prediction, comprising striosomes and matrix compartments.
• Striosomal neurons, though projecting to dopaminergic neurons, have unclear roles in reward prediction due to recording challenges.

Purpose of the Study:

• To investigate the role of striosomal neurons in reward prediction using advanced imaging techniques.
• To determine if striosomal neurons exhibit predictive activity related to reward or aversive stimuli.

Main Methods:

• Utilized a Cre-expressing mouse line (Sepw1-NP67) for selective striosomal neuron targeting.
• Employed endoscopic in vivo calcium imaging to record striosomal neuron activity during an odor-conditioning task.
• Monitored neural activity in the dorsomedial striatum (DMS) during learning and task performance.

Main Results:

• Striosomal neurons in the DMS displayed predictive activity towards odor cues associated with rewards or air puffs.
• This predictive activity correlated with the expected intensity of rewards or air puffs.
• Neural activity patterns were learning-stage specific, diminishing with continuous training, and some neurons responded to stimuli presentation.

Conclusions:

• Striosomes contribute to reward prediction via learning-stage specific neural ensembles.
• Striosomal neurons transmit reward and aversive signals to midbrain dopaminergic neurons.