Obesity-Induced Structural and Neuronal Plasticity in the Lateral Orbitofrontal Cortex.

Area of Science:

• Neuroscience
• Obesity Research
• Behavioral Science

Background:

• The orbitofrontal cortex (OFC) is crucial for integrating sensory information with food value to guide actions.
• Obesity is linked to impaired devaluation of food rewards, suggesting OFC dysfunction.
• This study investigates how obesity impacts OFC structure and function.

Purpose of the Study:

• To test the hypothesis that obesity alters OFC pyramidal neuronal structure and function.
• To determine if obesity reduces conditioned suppression of feeding.
• To explore the cellular mechanisms underlying OFC dysfunction in obesity.

Main Methods:

• Rats received restricted, extended, or no cafeteria diet access for 40 days.
• Conditioned suppression of feeding was tested using cues predicting foot shock.
• Golgi-cox staining and whole-cell patch clamp electrophysiology were used on lateral OFC neurons.

Main Results:

• Extended cafeteria diet access led to obesity and impaired conditioned suppression of feeding.
• Obesity induced morphological changes in basilar dendrites of lateral OFC pyramidal neurons.
• A depolarized resting membrane potential and decreased inhibitory synaptic transmission were observed in OFC neurons.

Conclusions:

• Obesity alters lateral OFC pyramidal neuron structure and function.
• Reduced inhibitory input to OFC neurons may impair the encoding of food value changes.
• These findings suggest a neural basis for altered food reward processing in obesity.