© iDesign, ShutterstockNeurons in the brain communicate via electrical impulses and neurotransmitters.
The whole human race just got a little dumber: A new analysis of the number of neurons, those brain cells that transmit thoughts, in the human brain has come back with a staggeringly lower number than thought -- 14 billion brain cells fewer, about the size of the babboon brain.
The highly quoted number of human brian cells, 100 billion, doesn't stand up to actual experimental inquiry, Suzana Herculano-Houzel, an assistant professor at the Universidade Federal do Rio de Janeiro, told the Nature neuroscience podcast NeuroPod.
The work was performed on four human brains, ages 50, 51, 54 and 71, from men who donated their brains to science. As The Guardian summarized:
The method involves dissolving the cell membranes of cells within the brain and creating a homogeneous mixture of the whole lot. You then take a sample of the soup, count the number of cell nuclei belonging to neurons (as opposed to other cells in the brain such as glia) and then scale up to get the overall number. The great advantage of this method is that unlike counting the number of neurons in one part of the brain and then extrapolating from that, it gets over the problem that different brain regions may have more or less densely packed neurons.
Comment: On the same subject, read Death by Roller Coaster.