A conserved brainstem region for instinctive behaviour control: The vertebrate periaqueductal gray
A. Vanessa Stempel
Abstract
Instinctive behaviours have evolved across animal phyla and ensure the survival of both the individual and species. They include behaviours that achieve defence, feeding, aggression, sexual reproduction, or parental care. Within the vertebrate subphylum, the brain circuits that support instinctive behaviour output are evolutionarily conserved, being present in the oldest group of living vertebrates, the lamprey. Here, I will provide an evolutionary and comparative perspective on the function of a conserved brainstem region central to the initiation and execution of virtually all instinctive behaviours—the periaqueductal gray. In particular, I will focus on recent advances on the neural mechanisms in the periaqueductal gray that underlie the production of different instinctive behaviours within and across species. • The periaqueductal gray (PAG) is central to the execution of instinctive behaviours. • Its function is evolutionarily conserved in vertebrates. • Behaviour-specific neuronal populations in the PAG are spatially organised. • A functional segregation of PAG projections to premotor regions exists.