A Molecular and Cellular Perspective on Human Brain Evolution and Tempo

Study in a Sentence: A new review provides an overview of the recent advances with in vitro models, genetic and molecular analyses leading to a deeper understanding of the human-specific specializations that modulate the brain—affecting size, brain function, and developmental timing of the brain that differ from other species.

Healthy for Humans: The authors highlight a number of studies showing key differences between humans and other species, such as rodents and nonhuman primates, in the regulation of genes. These species-specific functional effects have been discovered using human brain organoids, and applying modern genome-editing tools and genetic analysis reveals human-specific brain features. Differences in brain cell size, arrangements, and specialized cell types exist, and these human-specific features can be studied with the nonanimal methods across the wide range of brain development stages and in great molecular detail.

Redefining Research: This new publication builds on knowledge of significant structural and functional differences, notably between humans and other primates, which remain largely ignored in the evaluation of the translatability of animal studies, and in particular nonhuman primate use, to human health. This paper’s focus on species-specific developmental brain factors brings additional weight of evidence to crucial species differences, which requires systematic re-evaluation of the opportunity costs and harms in relying on nonhuman primate and rodent models in neuroscience and for the study of human neurodegenerative diseases.