Changes in brain activity after a diet-induced obesity

Area of Science:

• Neuroscience
• Obesity Research
• Medical Imaging

Background:

• Obese individuals exhibit diminished dorsolateral prefrontal cortex activation, crucial for inhibiting behavior and regulating satiety.
• It remains unclear if this neural deficit precedes or results from obesity.

Purpose of the Study:

• To investigate whether reduced prefrontal cortex activation is an acquired characteristic of obesity using an adult animal model.
• To compare brain activation patterns in lean versus diet-induced obese minipigs.

Main Methods:

• Seven diet-induced obese and nine lean adult minipigs were studied.
• Brain activation was mapped using single photon emission computed tomography (SPECT) and 99mTc-HMPAO to measure cerebral blood flow.
• Statistical parametric mapping (SPM) and MRI were used for data analysis.

Main Results:

• Obese minipigs showed deactivation in the dorsolateral and anterior prefrontal cortices compared to lean subjects.
• Reduced activation was also noted in the ventral tegmental area, nucleus accumbens, and nucleus pontis.
• Anterior/dorsolateral prefrontal and insular cortex activity correlated negatively with body weight.

Conclusions:

• The findings suggest that reduced prefrontal cortex activation in obesity is likely an acquired feature.
• This is supported by the observation of similar neural deficits in diet-induced obese minipigs.