This display of ‘lit-up’ cells has hidden wiring that would put Blackpool Illuminations to shame (and it's around 200,000-times smaller). Inside the nervous system of a young sea squirt (Ciona intestinalis), cells (blue dots) send signals to each other. One signal, called notch, tells a cell to develop into a neuron [nerve cell], while another, called delta, turns its neighbours’ notch signal ‘off’. It’s a complicated situation, calling for a mathematical model to unravel hidden details: other notch controllers send long distance signals along strips of developing cells (red), urging neurons to grow outwards in an irregular pattern (green). Mathematical modelling in biological research can be very powerful, in this case making predictions for how notch and delta work together in other tissues and organisms. Notch is heavily involved in human brain development, too, as well as helping to define the pattern of our fingers and toes in the womb.
Written by John Ankers
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.