“Our results suggest … administration of capsaicin in adult rats depresses the expression of beta/gamma-preprotachykinin, calcitonin … peptide and trkA messenger RNAs, and induces expression of vasoactive intestinal polypeptide and galanin messenger RNAs in sensory neurons, which may be … the capsaicin-induced degeneration of a subpopulation of sensory afferents.”