Caudate unit activity during operant feeding behavior in monkeys and modulation by cooling prefrontal cortex

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Primate Cognition

Background:

• The caudate nucleus (CD) plays a crucial role in motor control and reward-based learning.
• Understanding neuronal activity in the CD during complex behaviors like feeding is essential for deciphering brain function.

Purpose of the Study:

• To investigate the functional and distributional characteristics of neurons in the head of the caudate nucleus during an operant feeding task.
• To identify distinct neuronal populations and their roles in different phases of feeding behavior.

Main Methods:

• Electrophysiological recordings from 351 neurons in the head of the caudate nucleus of monkeys.
• An operant feeding task involving food presentation, bar pressing, and food ingestion.
• Dorsolateral prefrontal cortex cooling to assess its influence on neuronal activity and behavior.

Main Results:

• Neurons exhibited food-specific responses (18/45) and non-specific responses to visual stimuli (27/45) during presentation.
• Neuronal activity varied during bar pressing (continuous or press-related) and ingestion (chewing, gustatory, or movement-related).
• Distinct spatial distributions were observed for neurons responding during presentation and ingestion phases; prefrontal cortex cooling affected continuous B-phase responses.

Conclusions:

• The head of the caudate nucleus contains diverse neuronal groups with specialized functions, including food specificity, sensory integration, frontal cortex-driven non-motor responses, and motor-related activity.
• These neuronal functions may operate sequentially or in parallel, integrating sensory and motor systems for coordinated feeding behavior.
• The findings highlight the caudate nucleus's complex role in motivated behavior and action sequencing.