No abstract

Feeding and breathing are two functions vital to the survival of all vertebrate species. Throughout the evolution, vertebrates living in different environments have evolved drastically different modes of feeding and breathing through utilizing diversified orofacial and pharyngeal (oropharyngeal) muscles. The oropharyngeal structures are controlled by hindbrain neural circuits. The developing hindbrain shares strikingly conserved organizations and gene expression patterns across vertebrates, thus begs the question of how a highly conserved hindbrain generates circuits subserving diverse feeding/breathing patterns. In this review, we summarize major modes of feeding and breathing and principles underlying their coordination in many vertebrate species. We provide a hypothesis for the existence of a common hindbrain circuit at the phylotypic embryonic stage controlling oropharyngeal movements that is shared across vertebrate species; and reconfiguration and repurposing of this conserved circuit give rise to more complex behaviors in adult higher vertebrates. SIGNIFICANCE STATEMENT Understanding how a highly conserved hindbrain generates diverse feeding/breathing patterns is important for elucidating neural mechanisms underlying the execution and coordination of these two vital behaviors. Here, we first briefly summarize key modes of vertebrates feeding/breathing, discuss main principles coordinating feeding/breathing, and provide a unifying hypothesis for the existence of a shared oropharyngeal movement control circuit across species. By synthesizing behavior, structural and neural mechanisms for feeding/breathing functions across evolution, we believe that this review and our hypothesis can open new research avenues for elucidating the precise hindbrain circuits controlling feeding, breathing and other oropharyngeal functions.