Insulin action in the brain can lead to obesity

(Research Publication of the Max-Planck-Gesellschaft)

Fat-rich food makes you fat. Behind this simple equation lie complex signalling pathways, through which the neurotransmitters in the brain control the body’s energy balance. Scientists at the Cologne-based Max Planck Institute for Neurological Research and the Cluster of Excellence in Cellular Stress Responses in Ageing-associated Diseases (CECAD) at the University of Cologne have clarified an important step in this complex control circuit. They have succeeded in showing how the hormone insulin acts in the part of the brain known as the ventromedial hypothalamus. The consumption of high-fat food causes more insulin to be released by the pancreas. This triggers a signalling cascade in special nerve cells in the brain, the SF-1 neurons, in which the enzyme P13-kinase plays an important role. Over the course of several intermediary steps, the insulin inhibits the transmission of nerve impulses in such a way that the feeling of satiety is suppressed and energy expenditure reduced. This promotes overweight and obesity.

Please find more information in the press release attached.

Illustration: Visualisation of how insulin affects the SF-1 neurons of the hypothalamus. After stimulation with insulin, the SF-1 cells (red) form the signalling molecule PiP3 (green). (Blue: cell nucleus)
© MPI for Neurological Research