Artificial selection on brain size leads to matching changes in overall number of neurons

• DOI: 10.1111/evo.13805
• Publication Date: 2019-07-24T09:42:14Z
• Authors: Lucie Marhounová; Alexander Kotrschal; Kristina Kverková; Niclas Kolm; Pavel Němec
• Keywords: Poecilia

Neurons are the basic computational units of brain, but brain size is predominant surrogate measure functional capacity in comparative and cognitive neuroscience. This approach based on assumption that larger brains harbor higher numbers neurons their connections, therefore have a information-processing capacity. However, recent studies shown mass may be less strongly correlated with neuron counts than previously thought. Till now, no experimental test has been conducted to examine relationship between evolutionary changes number neurons. Here, we provide such by comparing artificial selection lines female guppies (Poecilia reticulata) >15% difference relative numerous demonstrated differences. Using isotropic fractionator, demonstrate large-brained females overall small-brained females, similar neuronal densities. Importantly, this holds also for telencephalon, key region cognition. Our study provides first direct evidence leads matching shows evolution intimately linked