Interplay among neural synchronization, excitability, variability, and sequentiality across time scales in rhythmic bursting

Abstract Rhythmic neural activity in the form of robust sequential activations is present in many neural systems at multiple description levels. Circuits generating such activity often involve intrinsic neuronal variability and interactions mediated by distinct synapse types. The control of sequential rhythms requires coordination across short and intermediate time scales to adapt to conditions within each cycle of the rhythm or to adjust excitability and speed to meet specific functional demands. In this work we analyze the interplay among neural synchronization, excitability, variability and sequentiality timing in rhythmic bursting. We analyze long intracellular and extracellular recordings of the pyloric CPG quantifying these aspects and reporting their relationships at multiple time scales including the modulation of cycle-by-cycle sequential dynamical invariants among key time intervals. The results of the relationship between specific sequence intervals at different time scales provide a novel view on the understanding of autonomous motor coordination in robust, yet time-flexible sequential rhythms, even during transient dynamics.