Differential encoding of action selection by orbitofrontal and striatal population dynamics.

Area of Science:

• Neuroscience
• Decision Making
• Neural Circuits

Background:

• Action selection is crucial for survival and involves corticostriatal circuits like the orbitofrontal cortex (OFC) and dorsomedial striatum (DMS).
• Previous research identified choice-specific neuronal responses in both OFC and DMS, but direct comparisons of population-level encoding are limited.

Purpose of the Study:

• To directly compare the population dynamics of the orbitofrontal cortex (OFC) and dorsomedial striatum (DMS) in encoding action selection.
• To determine whether OFC or DMS neural ensembles are more effective at representing an animal's behavioral choice.

Main Methods:

• Head-fixed mice were trained on an auditory-guided two-alternative choice task involving joystick manipulation.
• Simultaneous recordings of OFC and DMS ensemble spiking activity were performed using silicon microprobes.
• Trial-by-trial behavioral decoding was analyzed from concurrently recorded neural population dynamics.

Main Results:

• Both OFC and DMS exhibited neurons selective for specific stimulus-action associations.
• Neural population activity in the dorsomedial striatum (DMS) allowed for more accurate decoding of the animal's trial-by-trial choice compared to the orbitofrontal cortex (OFC).

Conclusions:

• Substantial regional differences exist in how the orbitofrontal cortex (OFC) and dorsomedial striatum (DMS) encode action selection.
• Dorsomedial striatum (DMS) neural dynamics appear more specialized than OFC dynamics for representing an animal's selected action.