Dr. Suzana Herculano-Houzel
The neuroscientist who showed what different brains are actually made of.
Neuroscientist, researcher, writer, educator...
A true native of Rio de Janeiro, Suzana Herculano-Houzel graduated from UFRJ, Case Western Reserve University, and Paris VI University. A former professor at UFRJ, she now works at Vanderbilt University in the United States. With the isotropic fractionator method (brain soup, really!), she was the first to actually count how many neurons the human brain has.
The Neuroscientist On Call
Read Dr. Herculano-Houzel's mind, ahn, blog about Life, The Brain, and Everything
Latest discoveries
How to get a bigger brain
We raised different numbers of fish in the same aquariums to make them grow bigger. Did they also grow bigger brains with more neurons? Yes… and no!
The minke whale brain in numbers
The minke whale brain is twice as large as the human brain… but it only has 1/5 as many cortical neurons, just like we predicted, and against earlier estimates.
How endothermic brains came to be
Maybe growing larger brains was inevitable once birds and mammals gained increased oxidative capacity…
Key discoveries
Longevity scales with numbers of cortical neurons
Body size and metabolic rate are mathematically irrelevant: the more the cortical neurons, the longer that birds and mammals live - and humans are no exception.
Brains use all the energy they can get
Contrary to what most neuroscientists expected, the brain is not a demand-based economy: its function is supply-limited, with many consequences for function and aging
T. rex and its cousins were the primates of their time
If they were warm-blooded, then their numbers of brain neurons can be estimated using modern chickens and ostriches… and they were baboon-like, which is terrifying!
All published papers
Learn with Dr. Herculano-Houzel!
Take the Crash Course in Neuroscience
The Crash Course in Neuroscience teaches you the principles and basic questions of the field in 14 short video lessons, with certification included.
Ask the Big Questions of Neuroscience
Watch her TED talks
Upcoming talks
Neuroday Lyon, December 4, 2025 (Lyon, France)
Brain, mind and consciousness, December 7-9, 2025 (Montreal, Canada)
São Paulo Innovation Week, May 2026 (São Paulo, Brazil)