Trillions of connections between millions of neurons, processing an uncountable number of signals every second – thinking about the brain is enough to make your head hurt. Yet making sense of its complexities remains the dream of neuroscience. This 3D map of a mouse brain, part of the MouseLight project, shows neurons arranged in complex patterns, stretching their spindly branches, known as axons, across different brain regions. A bit like archaeologists revealing ancient artefacts layer by layer, researchers used sensitive microscopy to pick out fluorescence in genetically modified neurons on the brain’s surface, before shaving away a thin slice of the brain and repeating the process hundreds of times. A 3D picture of each neuron emerges. So far 300 cells are mapped – information that is free to access and will grow as more neurons are added to this dizzying puzzle of 70 million pieces.
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.