The Blue Brain Project: A Virtual Rat Brain in a Box

blue brain project

Scientists of the Blue Brain Project claim that they have simulated a small section of the rat brain using a supercomputer and gathered new information on brain structure and function


The Blue Brain Project is a global research program that aims to create a detailed reconstruction and simulation of a rodent brain. It is part of a much larger, ambitious, and controversial US $1.1 billion dollar European project called the Human Brain Project, which aims to simulate a human brain. Both projects are led by Dr. Henry Markram, a neuroscientist at the Swiss Federal Institute of Technology in Lausanne (EPFL), and require the collaborative effort of many scientists, as well as IBM supercomputing power to process large datasets.

Researchers working on the Blue Brain Project have recently reported their first major result after 10 years of work in the journal Cell. Using a bottom-up approach, a technique where they examine neurons and their critical components before proceeding to examine how they work together, they have digitally reconstructed a ‘draft’ of a small part of the rat somatosensory cortex, a region of the brain which receives and interprets sensory information from rat whiskers and other regions of its body.

The published model contains a total 31,000 neurons, 55 layers of cells, and approximately 200 different neuron subtypes. These thousands of neurons are connected to each other by roughly 37,000 synapses. In addition to its remarkable structural detail, the simulated brain is also able to reproduce fundamental responses that are observed in real rat brain experiments, like whisker deflection. As a result, this virtual model will be highly useful to examine neural networks that are difficult to study experimentally.

Although the Blue Brain Project simulation is the most detailed to date, its researchers note that their conclusions are limited due to the omission of important components of the brain including glia, which are non-neuronal supporting cells, and blood vessels. Furthermore, it focuses on only one region in the brain in a juvenile rat. With the promise of additional data and increased computing power being used for the next ‘draft’, it will be interesting to see what the Blue Brain Project delivers next.


Reconstruction and Simulation of Neocortical Microcircuitry. Markram H, Muller E, Ramaswamy S, Reimann MW, Abdellah M, Sanchez CA, Ailamaki A, Alonso-Nanclares L, et al. Cell, Volume 163, Issue 2, Pages 456-492.

The Blue Brain Project Website:






Written by Fiona Wong, PhD