How folds form on the brain surface
The molecular process behind the characteristic folding on the brain’s surface has been found in ferrets.
Folds in the brain’s outer layer, or cortex, create a bigger surface area for packing in more neurons. The evolution of folds in some mammals is thought to have brought about higher intelligence, but studying the formation of folds is tricky.
In 2013, researchers from Kanazawa University identified fibroblast growth factors (FGFs), multipurpose proteins that promote tissue and cell growth, as a possible cause of excessive folding in ferret brains.
The team has now genetically altered ferret embryos in the womb to enhance or curtail FGF activity. They found that increased FGF signalling helps folds form by thickening the upper layer of the cortex, whereas inhibiting FGF signalling visibly reduced folding.
Further studies could uncover how abnormal folding in the human brain contributes to conditions such as schizophrenia and autism.
- eLife 6, e29285 (2017). doi: 10.7554/eLife.29285
|Division of Medical Neuroscience, KU, Japan||1|