From the outside your brain looks symmetrical, right down to the creases. On the inside, though, it’s a different story. The cells of your brain have different structures and functions on the left and the right: for example, the left mostly deals with language. Researchers working on zebrafish are looking at how the developing brain defines which side is which. Two oval-shaped structures in the fishes forebrain – the left and right habenulae (pictured)– usually contain different types of neurons [nerve cell]. In experimental fish with a gene called tcf7l2 switched off, both sides developed ‘left’ type neurons (shown in green, with the brain’s supporting structure in purple). Examining how asymmetry develops can help us understand what influences the identities of cells, and teach us about schizophrenia and depression – conditions linked with disruption of the brain’s normal asymmetry. Hopefully soon we’ll know our lefts from our rights.
Written by Esther Redhouse White
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.