Now in our 12th year of bringing you beautiful imagery from biomedical science every day

Search the archive of over 4000 images

Over the Brainbow
28 September 2015

Over the Brainbow

Dubbed 'brainbow', an exciting new imaging technique is challenging our understanding of how the brain develops. A well-established principle in development is activity-dependent pruning of neural connections: neurons initially make lots of contacts with neighbouring cells, then many are lost, leaving only the functionally most important links. In the visual system, this was thought to lead to an almost one-on-one connection between intermediate cells of the retina, retinal ganglion cells (RCGs) and relay cells of the thalamus, in the forebrain. When researchers labelled RGCs with different fluorescent proteins, they expected to find clusters of the same colour, showing that the connections on each relay cell all came from a single RCG. Instead, their images revealed a kaleidoscope of intertwined colours, as shown in this mouse brain. This suggests that multiple RCGs contact each relay cell, and hints that neural development is yet more complex than we imagined.

Written by Emmanuelle Briolat

Search The Archive

Submit An Image

Follow on Tumblr

Follow on Instagram

What is BPoD?

BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

Read More

BPoD is also available in Catalan at with translations by the University of Valencia.