Targeted activation or ablation of NAV1.8-expressing neurons in lumbar dorsal root ganglia of mice modulates knee hyperalgesia

Abstract

Purpose: The knee joint is highly innervated by sympathetic neurons and sensory afferents, most of which are nociceptors (high threshold pain-sensing neurons). NaV1.8 is a voltage-gated sodium channel mainly expressed in nociceptive neurons, the cell bodies of which are located in dorsal root ganglia (DRG). To study the mechanisms of osteoarthritis (OA)-associated pain, we have used NaV1.8-tdTomato reporter mice to document the sensory innervation of murine knee joints. We also reported that systemic chemogenetic inhibition of NaV1.8-expressing neurons decreases knee hyperalgesia in the early stages of experimental OA induced by destabilization of the medial meniscus.