Increase of extracellular dopamine in primate prefrontal cortex during a working memory task

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neurochemistry

Background:

• Dopamine in the prefrontal cortex is crucial for cognitive functions.
• Previous research lacked direct measurement of prefrontal dopamine during cognitive tasks.

Purpose of the Study:

• To investigate extracellular dopamine levels in the primate prefrontal cortex during a working memory task.
• To determine the relationship between dopamine concentration and working memory performance.

Main Methods:

• In vivo microdialysis was used to measure extracellular dopamine in monkeys.
• Monkeys performed a delayed alternation task (working memory) and a sensory-guided control task.

Main Results:

• A significant increase in dopamine was observed in the dorsolateral prefrontal cortex during the working memory task compared to control and resting states.
• Dopamine levels increased in the lip areas of the principal sulcus, suggesting a role in working memory.
• Premotor dopamine increased during both tasks, indicating its involvement in motor responses.

Conclusions:

• Extracellular dopamine in the dorsolateral prefrontal cortex significantly increases during working memory tasks.
• This finding supports the role of dopamine in prefrontal cortex-dependent cognitive processes.
• Premotor dopamine is important for executing motor responses.