Brains Kept on Toes by Ancestral Circuits

Chance disfavors the unprepared mind, which may explain why the brains of animals as evolutionarily divergent as zebrafish and mice share neuronal circuits associated with vigilance. Animals lacking these circuits—the neuronal basis of alertness—would likely respond more slowly to threatening stimuli, or propitious stimuli, for that matter, limiting their prospects for survival.The neural basis of alertness found in zebrafish and mice may also occur in humans, suggested the director