Spontaneous neural activity changes after bariatric surgery: A resting-state fMRI study

Area of Science:

• Neuroscience
• Metabolic disorders
• Bariatric surgery

Background:

• Obesity-related metabolic disorders can alter brain structure and function.
• Reversibility of these brain changes after weight loss is not well understood.
• Bariatric surgery offers a model to study longitudinal brain changes post-weight loss.

Purpose of the Study:

• To investigate longitudinal changes in spontaneous neural activity after bariatric surgery.
• To determine if these neural changes correlate with cardiometabolic improvements.
• To compare neural activity in obese versus normal-weight individuals.

Main Methods:

• Longitudinal study of 57 severely obese participants undergoing bariatric surgery (SG, BPD, RYGB).
• Assessed fractional amplitude of low frequency fluctuations (fALFF) and regional homogeneity (ReHo) pre- and post-surgery (4, 12, 24 months).
• Used voxel-based morphometry (VBM) for grey matter density and an independent Human Connectome Project (HCP) sample for comparison.

Main Results:

• Global increase in fALFF signal post-surgery, particularly in the dorsolateral prefrontal cortex, precuneus, and visual cortex, peaking at 4 months.
• Increased fALFF correlated with increased grey matter density and improvements in weight and cardiometabolic factors (e.g., blood pressure).
• Normal-weight individuals in the HCP sample showed higher fALFF signals compared to obese individuals.

Conclusions:

• Bariatric surgery-induced weight loss and metabolic improvements are linked to increased global and regional neural activity (fALFF).
• Findings suggest an early recovery of neural activity levels post-surgery.
• Higher fALFF in normal-weight individuals supports the observed post-surgical neural recovery.