New publication: "Novel Evoked Synaptic Activity Potentials (ESAPs) elicited by Spinal Cord Stimulation."
In a rodent Spinal Cord Stimulation (SCS) model we report that in addition to fast Evoked Compound Action Potentials (ECAPs) there are later slower signals we call: Evoked Synaptic Activity Potentials (ESAPs).

Why does this matter for Spinal Cord Stimulation (SCS) therapy:
1) ECAPs reflect only conduction of dorsal column axons, not necessarily a spinal circuit response. But ESAPs reflect network/synaptic activity within the dorsal horn. (We definitively show ESAPs are not myogenic). ESAPs may be a unique maker of pain / SCS state.
2) Slow potentials in human spinal electrophysiology have been studied for decades. Our study bridges this vast literature into modern SCS but showing slow signals from the dorsal horn can be evoked/detected with percutaneous SCS leads (i.e. existing SCS hardware).
3) But we show ESAPs require more nuance (than ECAPs) to detect. We suggest this is a *virtue* in providing insights for SCS optimization and mechanisms. It's no coincidence the originators of the pain gate-control-theory (Wall & Melzack) studied slow spinal potentials!
https://www.eneuro.org/content/10/5/ENEURO.0429-22.2023.long