Larger rodent brains are made of more and larger neurons

Herculano-Houzel S, Mota B, Lent R, Proc Natl Acad Sci USA (2006)


This was our first comparative study using the isotropic fractionator, comparing rodent species that are readily available in Brazil: the common laboratory mouse, hamster, rat and guinea pig, as well as the large agouti and the giant capybara. These animals vary more widely in body mass (by almost 1200 x) than in brain mass (by 123 x), in accordance with the general rule that body mass scales together with, but faster than, brain mass.

We find that the cellular scaling rules that apply to rodent brains are close to what the literature would predict: larger brain structures are composed of larger numbers of neurons, with decreasing neuronal densities, and increasing non-neuronal/neuronal cell ratios.


Original article:

Herculano-Houzel S, Mota B, Lent R (2006) Cellular scaling rules for rodent brains. Proc Natl Acad Sci USA 103, 12138-12143.