Environmental temperature change and the stability of nervous systems in marine animals
Many kinds of marine animals are poikilothermic, meaning that they tolerate substantial changes in core body temperature. This contrasts with homeotherms, which regulate temperature, either internally or by actively seeking locations in the environment in specific temperature ranges. The underlying mechanisms of temperature resilience are poorly understood, and do not occur trivially in any biochemical system where rates of the underlying processes are strongly temperature dependent. This presents several deep open questions: How does the nervous systems and physiology of poikilotherms maintain function across wide temperature ranges? What are the limits of this resilience? Can we reverse engineer the dynamics and structure of systems that are inherently temperature robust? I will present recent findings from a theory-driven experimental collaboration that addresses these questions in a classic model system: the crustacean stomatogastric central pattern generator (CPG). When characterising temperature and pH dependent changes in CPG dynamics, we found substantial variability in the critical temperature and pH at which crustacean CPG motor activity ‘crashes’. In other words, as pH and temperature are independently ramped, CPG preparations reversibly transition from their normal, physiological firing pattern to aberrant, seizure like activity and/or silence. Remarkably, despite large variation from animal to animal, we uncovered a universal mathematical structure in the network activity that could qualitatively account for all transitions in CPG activity that we observed. These findings pave the way for current and future work in which we will attempt to control CPG activity using realtime, data driven models of CPG dynamics.
This work is supported by the Kavli Foundation.