Medical Research Council - London Institute of Medical Sciences

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

Millions and Millions

Information on brain cell connections in unprecedented detail

28 July 2021

Millions and Millions

Scientists first described the basic structures of the brain back in the first century CE, yet they could only speculate on how it worked. We now know that there are roughly 100 billion cells in a typical human brain, wired together in incredibly complex patterns. Thanks to advances in high-powered microscopy, today’s researchers are now able to see individual brain cells and trace the connections between them in unprecedented detail. These images show different types of information about the three-dimensional structure of 50,000 nerve cells and 133.7 million connections in a single cubic millimetre of human brain tissue: all cells (top left), two different types of nerve cells (top right and bottom left) and supporting cells known as glia (bottom right). While we know more than the early anatomists, understanding how all this complexity generates thoughts and actions is still one of the biggest remaining challenges in biomedical science today.

Written by Kat Arney

Search The Archive

Submit An Image

What is BPoD?

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.

Read More

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