Signal propagation along the axon

Sylvain Rama (1) , Mickael Zbili (1) , Dominique Debanne (1)

1 UNIS - Inserm U1072 - Unité de Neurobiologie des canaux Ioniques et de la Synapse

Axons link distant brain regions and are usually considered as simple transmission cables in which reliable propagation occurs once an action potential has been generated. Safe propagation of action potentials relies on specific ion channel expression at strategic points of the axon such as nodes of Ranvier or axonal branch points. However, while action potentials are generally considered as the quantum of neuronal information, their signaling is not entirely digital. In fact, both their shape and their conduction speed have been shown to be modulated by activity, leading to regulations of synaptic latency and synaptic strength. We report here newly identified mechanisms of (1) safe spike propagation along the axon, (2) compartmentalization of action potential shape in the axon, (3) analog modulation of spike-evoked synaptic transmission and (4) alteration in conduction time after persistent regulation of axon morphology in central neurons. We discuss the contribution of these regulations in information processing.

Keywords: Axon; Ion channel distribution

Domains: Neurons and Cognition [q-bio.NC]; Neurobiology

Sylvain Rama, Mickael Zbili, Dominique Debanne. Signal propagation along the axon. Current Opinion in Neurobiology, 2018, 51, pp.37-44. ⟨10.1016/j.conb.2018.02.017⟩. ⟨hal-01963472⟩