Proteins called semaphorins control the pathway of nerve connections in the brain involved in hunger
While it may be tempting to blame your rumbling tummy for feelings of hunger, it’s actually the brain the controls food intake – specifically a region known as the hypothalamus, a small clump of nerve cells buried deep in the centre of the brain. Using zebrafish as a convenient laboratory model for human brains, researchers are figuring out how the wiring in the hypothalamus controls bodyweight. This image shows the hypothalamus from a zebrafish, which has been stained to show the circuit of nerve cells that control body weight (red and green), revealing bright pathways of connections and dark regions that the nerve cells avoid. These connections are controlled by molecules known as semaphorins, which act as a ‘road map’ for the brain. Interfering with semaphorins leads to increased body weight, and alterations in sempahorin genes are found in some overweight humans, confirming this important link between brain wiring and bodyweight.
Written by Kat Arney
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