A basal ganglia circuit for evaluating action outcomes

Area of Science:

• Neuroscience
• Decision-making research
• Behavioral neuroscience

Background:

• The basal ganglia are critical for decision-making, particularly action selection.
• The precise role of basal ganglia circuitry in evaluating action outcomes remains less understood.
• Understanding outcome evaluation is key to deciphering complex decision-making processes.

Purpose of the Study:

• To investigate the role of the habenula-projecting globus pallidus (GPh) in evaluating action outcomes.
• To identify the specific basal ganglia inputs regulating GPh function in outcome evaluation.
• To elucidate how the GPh integrates information for decision-making.

Main Methods:

• Classical conditioning tasks in mice to assess outcome evaluation.
• Optogenetic manipulation of GPh neuron activity to mimic evaluation signals.
• Cell-type-specific synaptic manipulations to probe input functions.
• Rabies-virus-assisted monosynaptic tracing to map GPh circuit connectivity.

Main Results:

• Individual mouse GPh neurons bidirectionally encode outcomes as better or worse than expected.
• Optogenetic GPh stimulation/inhibition effectively reinforced/discouraged actions.
• Specific inhibitory and excitatory inputs to the GPh were necessary for evaluating negative and positive feedback, respectively.
• The GPh receives inhibitory input from striatum (both compartments) and excitatory input from the subthalamic nucleus.

Conclusions:

• The GPh is essential for evaluating action outcomes within the basal ganglia.
• Distinct basal ganglia circuits channel information for action selection versus outcome evaluation.
• The GPh integrates opposing valence information to signal outcome expectation deviations.