Neuron-astrocyte metabolic coupling in spinal sensorimotor integration
Rémi Bos
PI Team SpiCCI – Spinal Cord and Cerebrospinal Fluid Interface
INT, Marseille

Abstract
Glial cells, long viewed as passive support for neurons, are now recognised as active regulators of central nervous system function. Through a continuous dialogue with neurons, astrocytes maintain ionic homeostasis, supply energy and adjust network excitability. This dialogue is highly plastic, but vulnerable to injury and inflammation, and its disruption contributes to sensory and motor impairments. Having shown that astrocytes regulate spinal motor networks through potassium buffering, we asked whether they could also do so through their energy metabolism. Astrocytes produce lactate and deliver it to active neurons, and lactate is now recognised as a signal able to regulate excitability. Yet whether this coupling also controls inhibitory circuits remains largely unknown. In this talk, I will address this question in the superficial dorsal horn, the first relay for somatosensory information. Combining electrophysiology, pharmacology and two-photon imaging of genetically encoded lactate sensors, we show that afferent activity drives lactate release by astrocytes and its uptake by inhibitory interneurons. In these interneurons, lactate increases excitability through ATP-sensitive potassium channels and strengthens GABAergic control of sensory input. Together, these findings identify neuron-astrocyte metabolic coupling as a new layer of regulation of spinal sensorimotor integration. They also raise the question of how this coupling is altered in spinal cord injury, neuroinflammation and neurodegenerative diseases.

Invited by Thomas Marissal
Monday 2 November 2026 at 11.00 am – Inmed conference room