||Traumatic brain injury is an incurable neurodegenerative condition affecting more than 13 million individuals worldwide. To address the emotional and economic burden to patients, their families, and society, innovative methods are desperately needed to understand better the mechanism leading to neuroregeneration. Axonal plasticity and phagocyte motility are key processes involved in neuroregeneration. Although their chemical determinants have been extensively studied, the role of physical cues is poorly understood due to technical limitations. In this highly interdisciplinary project, we will develop innovative micro- and nanoscale diamond probes to modulate temperature-sensitive ion channels in neurons and phagocytes. The project consists of 3 parts with increasing complexity, risk and potential gain. In part 1, existing prototypes of milli-probes will be used to analyze temperature-dependent axon plasticity and phagocyte motility. In parallel (part 2), single axon behavior and microglial motility under temperature micro-gradients will be analyzed using newly-developed micro-probes. In part 3, antibody-coupled nano-probes targeted to selected membrane proteins will be used for accurate stimulation of specific axons or microglial branches. This highly interdisciplinary approach paves the way for a completely new research line to investigate the effects of temperature gradients on ion channels without classical artifacts induced by lasers or microheaters.