Environmentally induced return to juvenile‐like chemosensitivity in the respiratory control system of adult bullfrog Lithobates catesbeianus

摘要

Key points class="unordered" style="list-style-type:disc" id="tjp7438-list-0001">The degree to which developmental programmes or environmental signals determine physiological phenotypes remains a major question in physiology.Vertebrates change environments during development, confounding interpretation of the degree to which development (i.e. permanent processes) or phenotypic plasticity (i.e. reversible processes) produces phenotypes.Tadpoles mainly breathe water for gas exchange and frogs may breathe water or air depending on their environment and are, therefore, exemplary models to differentiate the degree to which life‐stage vs. environmental context drives developmental phenotypes associated with neural control of lung breathing.Using isolated brainstem preparations and patch clamp electrophysiology, we demonstrate that adult bullfrogs acclimatized to water‐breathing conditions do not exhibit CO2 and O2 chemosensitivity of lung breathing, similar to water‐breathing tadpoles.Our results establish that phenotypes associated with developmental stage may arise from plasticity per se and suggest that a developmental trajectory coinciding with environmental change obscures origins of stage‐dependent physiological phenotypes by masking plasticity.