The Human Body
How many neurons are in the average adult human brain?
Answer
86,000,000,000 neurons
The classic '100 billion' figure was folklore until neuroscientist Suzana Herculano-Houzel's lab literally dissolved brains into 'soup' and counted: 86 billion. Each neuron can connect to thousands of others, giving you more synapses than there are stars in the Milky Way.
Source: Azevedo et al. (Herculano-Houzel lab), Journal of Comparative Neurology, 2009
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