Exploratory activity during a consecutive period of 45 minutes (9 intervals, 5 min/interval) after introduction of the rat into the novel chamber. Compared to naïve rats (n = 14), intrathecal catheter implanted rats (n = 14) do not have significant alterations in exploratory activity. Rats with intradermal injection of capsaicin (1%, 50 μl) (n = 6) demonstrated a reduction of exploratory activity, including decreased number of photobeams broken (A), shortened travel distance (B), decreased active time (C), increased resting time (D), shortened rearing time (E), and decreased number of rearing events (F). The capsaicin-injected group was compared to the other two groups. *p < 0.05.