IT SEEMS our brains are a model of efficiency. Mammalian neurons transmit electrical signals using much less energy than suspected.
Our brain cells have long been thought to be inefficient, but this notion was based on experiments carried out in the 1930s on squid brain cells, chosen as they are large and easy to work on. Henrik Alle of the Max Planck Institute for Brain Research in Frankfurt, Germany, and his colleagues decided to explore the efficiency of rat brain cells, which are more similar to those of humans.
To transmit electrical signals along a neuron, a strong difference in…
