Nav1.8 relation with chronic inflammatory pain and aging

MESSINA, DIEGO N.; FOSCOLO, MABEL R.; ACOSTA, CRISTIAN G.

Virtual

Congreso; XXXV Congress of the Argentine Society for Research in Neuroscience; 2020

SAN, IBRO-LARC

We aimed to determine the expression pattern of Nav1.8 in primary sensory neurons of the DRG in young adult rats (3-6 months) and aged rats (12-18 months), and correlate this pattern with the behavioral changes observed in a model of chronic inflammatory pain. We quantified the expression of Nav1.8 by ABC/DAB immunohistochemistry in serial sections of L4 and L5 DRGs from Wistar rats aged 3, 6, 12 and 18 months. We induced inflammation with an intradermal injection of Complete Freund´s Adjuvant solution (CFA) in 8 3-months-old and 12 14-months-old rats. We evaluated two types of pain during 120 days after CFA: spontaneous pain, using the spontaneous foot lifting test (SFL) and evoked pain, with the von Frey test. Nav1.8 staining intensity in small neurons was lower in 3-month-old than in 6-month-old rats (36.5±0.9% vs 49.9±1.3%, p