Sensitization of capsaicin responses after acute (A) and chronic (B) oxaliplatin treatment; Sensitization of responses to icilin (C), but not WS12 (D), after oxaliplatin treatment. A. Graph showing the average magnitude of desensitization (2nd bar) normalised to the first response (1st bar) in vehicle treated neurons. Acute oxaliplatin treatment resulted in significantly enhanced second responses (3rd bar), compared to the first capsaicin response, that was reversed by preincubation with 5 μM CB2 agonist GW833972 (4th bar). B. Chronic treatment with oxaliplatin for 48 hours also enhanced responses to 200 nM capsaicin (n.s. at 5 μg/ml oxaliplatin, but highly significant at 20 and 50 μg/ml oxaliplatin). C. Vehicle treated neurons responded to 1 μM icilin with calcium influx (1st bar), and a smaller second response following washout (2nd bar). Pretreatment with 20 μg/ml oxaliplatin before the second icilin stimulus significantly enhanced responses to 1 μM icilin (3rd bar), and significantly higher than the second icilin response without oxaliplatin (P = 0.005). Similarly, chronic oxaliplatin treatment (20 μg/ml for 24 hours), also resulted in significantly enhanced second responses to 1 μM icilin compared to those without oxaliplatin (P < 0.05). D. Vehicle treated neurons responded to the TRPM8 specific ligand WS-12 (20 μM stimulus), with calcium influx (1st bar). Following washout, a second 20 μM WS-12 stimulus resulted in a reduced response (2nd bar), that was unaffected by the presence of oxaliplatin.