Dorsolateral Striatum Engagement Interferes with Early Discrimination Learning

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Cognitive Neuroscience

Background:

• Current models suggest the dorsolateral striatum (DLS) and dorsomedial striatum (DMS) mediate stimulus-driven and goal-directed learning, respectively.
• The DLS is traditionally associated with well-learned, automated behaviors, but recent evidence points to its involvement early in training.

Purpose of the Study:

• To investigate the causal role of the DLS in early-stage learning of stimulus-response associations.
• To examine the impact of DLS activity on touchscreen discrimination learning and associated neural plasticity.

Main Methods:

• In vivo optogenetic photosilencing was used to selectively inhibit DLS activity during early touchscreen discrimination tasks.
• Electrophysiological recordings and plasticity measurements were employed to assess circuit-level changes.

Main Results:

• DLS recruitment during early learning interferes with touchscreen discrimination performance.
• The direct output pathway of the DLS is preferentially activated and causally involved in this early learning process.
• Inhibiting the DLS leads to plasticity alterations in the prelimbic cortex-DMS circuit.

Conclusions:

• The DLS is recruited early in the construction of stimulus-elicited actions, contributing to eventual behavioral automation.
• While essential for automating behavior, DLS engagement comes at the cost of initial learning efficiency.
• Modulating DLS function can alter plasticity in connected circuits, offering insights into learning mechanisms.