The role of genetics in early brain development has been extensively studied but little is known about environmental stimuli such as light-dark cycles. To examine how light affects brain development after birth, the authors studied the migration of cerebellar neurons in newborn mice during periods of light and dark. They found that neurons migrated faster during light cycles and slower during dark periods. Cerebellar levels of insulin-like growth factor 1 (IGF-1) were also higher during light cycles compared to dark periods. Specifically, light-induced elevation of insulin-like growth factor 1 (IGF-1) from differentiating neurons and blood vessels appears to accelerate neuronal migration of these developing neurons. They suggest that light stimuli modulate cerebellar granule cell migration by altering the levels and activity of IGF-1 and its receptors, respectively. The authors suggest that these results may also be relevant for understanding the effects of natural light exposure on neuronal growth and brain development in human infants.
Li, Ying et al.: Light stimuli control neuronal migration by altering of insulin-like growth factor 1 (IGF-1) signaling. Proc. Natl. Acad. Sci. USA [Epub ahead of print, January 30, 2012] doi: 10.1073/pnas.1111326109