Complementary Control over Habits and Behavioral Vigor by Phasic Activity in the Dorsolateral Striatum

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Systems Neuroscience

Background:

• The basal ganglia are implicated in habit formation and behavioral vigor.
• The precise relationship between these two functions and the role of the dorsolateral striatum (DLS) remains unclear.
• Understanding the temporal dynamics of DLS activity is crucial for deciphering its role in learned behaviors.

Purpose of the Study:

• To investigate the role of phasic dorsolateral striatum (DLS) activity in regulating behavioral vigor and habit formation.
• To determine the critical timing of DLS activity for the expression of habitual behaviors.
• To explore the relationship between DLS function and outcome insensitivity in learned tasks.

Main Methods:

• Utilized male Long-Evans rats in response-based and cue-based maze-running tasks.
• Employed optogenetics to precisely excite or inhibit DLS activity at specific behavioral time points.
• Assessed behavioral vigor, run duration, deliberative movements, and habit strength using outcome devaluation techniques.

Main Results:

• Phasic DLS excitation at behavior onset decreased run duration and deliberative behaviors, indicating enhanced vigor and habit.
• DLS inhibition at run start primarily affected performance after outcome devaluation, reducing vigor and causing habit loss.
• DLS activity at behavior initiation critically regulates both the speed and habitual nature of learned maze-running behaviors.

Conclusions:

• Phasic DLS activity at behavior initiation is a key regulator of behavioral vigor and habit.
• These findings link previously disparate aspects of habitual behavior, including performance, vigor, and outcome insensitivity.
• The critical timing of DLS involvement at behavior onset offers potential therapeutic targets for habit-related disorders.