The evolution of brain neuron numbers in amniotes.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35254911.
- Also identified by DOI 10.1073/pnas.2121624119 and PMC identifier 8931369.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
SignificanceThe evolution of brain processing capacity has traditionally been inferred from data on brain size. However, similarly sized brains of distantly related species can differ in the number and distribution of neurons, their basic computational units. Therefore, a finer-grained approach is needed to reveal the evolutionary paths to increased cognitive capacity. Using a new, comprehensive dataset, we analyzed brain cellular composition across amniotes. Compared to reptiles, mammals and birds have dramatically increased neuron numbers in the telencephalon and cerebellum, which are brain parts associated with higher cognition. Astoundingly, a phylogenetic analysis suggests that as few as four major changes in neuron-brain scaling in over 300 million years of evolution pave the way to intelligence in endothermic land vertebrates.
Medical subject headings
- Biological Evolution
- Brain
- Cell Count
- Neurons
- Vertebrates