TRPV1 and pulpitis: Of note, lipopolysaccharides (LPS) from Gram (−) bacteria upregulated TRPV1 expression in TG [47], and Complete Freund’s Adjuvant (CFA) upregulated TRPV1 in TG neurons innervating adjacent teeth [48], suggesting the potential contribution of TRPV1 to tooth pain under the pulpitis condition.