Central insulin modulates food valuation via mesolimbic pathways

Area of Science:

• Neuroscience
• Metabolism
• Endocrinology

Background:

• Central insulin plays a role in regulating eating behavior at the intersection of metabolic and hedonic drives.
• Understanding how insulin influences food value perception is crucial for metabolic health.

Purpose of the Study:

• To investigate the effects of intranasal insulin (INI) on the neural processing of food cues and palatability.
• To examine the modulation of mesolimbic pathways by INI in relation to food value.
• To explore differences in INI's effects between individuals with normal insulin sensitivity and insulin resistance.

Main Methods:

• Pharmacological functional magnetic resonance imaging (fMRI) was employed.
• Participants rated the palatability of food pictures and attractiveness of control items after receiving INI or placebo.
• Connectivity analyses were performed to assess neural pathway modulation.

Main Results:

• INI reduced food palatability ratings and value signals in mesolimbic regions in participants with normal insulin sensitivity.
• Insulinergic inhibition of projections from the ventral tegmentum to the nucleus accumbens was observed.
• In insulin-resistant participants, reduced food values and aberrant central insulin action were noted.

Conclusions:

• Central insulin modulates the neural cross-talk between homeostatic and non-homeostatic feeding systems.
• INI influences food cue value through mesolimbic pathway modulation.
• Dysfunctions in these neural interactions may contribute to metabolic disorders.