Distinct Lateral Prefrontal Regions Are Organized in an Anterior-Posterior Functional Gradient

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Primate Neurophysiology

Background:

• The dorsolateral prefrontal cortex (dlPFC) is crucial for higher-order cognition, including working memory and attention.
• A global anterior-posterior functional gradient exists in the dlPFC, but its nature (smooth vs. areal) is debated.

Purpose of the Study:

• To investigate whether the dlPFC's functional gradient is smooth or composed of distinct areal gradients.
• To analyze single-neuron physiological properties along the dlPFC's anterior-posterior axis.

Main Methods:

• Recorded single-neuron activity in the dlPFC of nonhuman primates during a memory-guided saccade task with distractor.
• Analyzed physiological properties and spatial information representation across the anterior-posterior axis.

Main Results:

• Single-neuron physiological properties were best described by an areal gradient, supporting distinct functional regions.
• Population analyses revealed a distributed representation of spatial information across the dlPFC.
• Working memory was more prominent in posterior dlPFC regions but also present anteriorly.

Conclusions:

• The findings validate functional boundaries between anatomically defined dlPFC regions.
• Highlight the distributed nature of working memory computations across the dlPFC.
• Suggest functional segregation within the dlPFC, analogous to other brain systems.