Beyond the Connectome: Variability, Compensation and Modulation in Rhythmic Neuronal Networks

Abstract:

I will summarize recent theoretical and experimental work that shows that similar circuit outputs can be produced with highly variable circuit parameters.  This work argues that the nervous system of each healthy individual has found a set of different solutions that give “good enough” circuit performance.  Studies using the rhythmic central pattern generating networks in the crustacean stomatogastric nervous system argue that synaptic and intrinsic currents can vary far more than the output of the circuit in which they are found.   These data have significant implications for the mechanisms that maintain stable function over the animal’s lifetime, and for the kinds of changes that allow the nervous system to recover function after injury.  In this kind of complex system, merely collecting mean data from many individuals can lead to significant errors, and it becomes important to measure as many individual network parameters in each individual as possible.  Multiple solutions in the population provide a substrate for evolutionary change in response to environmental perturbations.