The human brain in numbers: a linearly scaled-up primate brain

The human brain has often been viewed as outstanding among mammalian brains: the most cognitively able, the largest-than-expected from body size, endowed with an overdeveloped cerebral cortex that represents over 80% of brain mass, and purportedly containing 100 billion neurons and 10x more glial cells. Such uniqueness was seemingly necessary to justify the superior cognitive abilities of humans over larger-brained mammals such as elephants and whales. However, our recent studies using a novel method to determine the cellular composition of the brain of humans and other primates as well as of rodents and insectivores show that, since different cellular scaling rules apply to the brains within these orders,…

• CN
  Conselho Nacional de Desenvolvimento Científico e Tecnológico
• FC
  Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro