Cholinergic network modulation in disinhibited eating behavior

Area of Science:

• Neuroscience
• Obesity Research
• Neuroimaging

Background:

• Cholinergic systems modulate brain reward pathways crucial for salience processing in obesity.
• In vivo evidence of altered acetylcholine transmission in human obesity and abnormal eating behavior is lacking.

Purpose of the Study:

• To investigate in vivo changes in nicotinic acetylcholine receptors (nAChR) availability and brain network activation in individuals with obesity compared to normal-weight controls.
• To explore the relationship between nAChR availability, eating behavior, and brain activation patterns in response to food cues.

Main Methods:

• Simultaneous positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) were used.
• Twenty individuals with obesity and sixteen normal-weight controls were studied.
• Participants were exposed to visually salient food cues.

Main Results:

• Individuals with obesity showed increased α4β2* nicotinic acetylcholine receptors (nAChR) availability in response to food cues, particularly those with high disinhibited eating.
• Normal-weight controls showed no change in nAChR availability.
• Brain activation shifted from the dorsal attention network in controls to the salience network in individuals with obesity.

Conclusions:

• Increased α4β2* nAChR availability and altered network activation in response to food cues are observed in human obesity.
• These findings suggest fundamental differences in sensory cue detection and reward processing in obesity.
• Further research into α4β2* nAChR is warranted for potential weight loss treatments targeting hedonic overeating.