Figure 4.

Sumatriptan reduces nitroglycerine-induced hypersensitivities. Nitroglycerine- (red traces/columns), vehicle- (black traces/columns), and nitroglycerine/sumatriptan-treated (blue traces/columns) rats were tested on two baseline- and one time point post injection for their responses to mechanical- and heat stimuli. Nitroglycerine and sumatriptan injections were performed at time point 0, as indicated by the grey dashed line (A,B). At the testing time point post injection, all groups were subjected to the testing sequence (C–K). (A) von Frey test/mechanical paw withdrawal thresholds. (B) Plantar heat test/radiant-heat induced paw-withdrawal latency. (C–F) Automated classification of voluntary behaviours in the spectroscopy apparatus. The parameters are ordered in general behaviours (C), tracklength (D), overall activity (E), and velocity (F). (G) 3 chamber apparatus/time spent in a compartment with an unknown animal. (H) Elevated plus maze/time spent in open arm exploration. (I) Splash-test/time in induced grooming behaviour. (J) Saccharine preference. (K) Nest building scoring (median ± 95% confidence interval, Kruskal-Wallis test with Dunn's multiple comparison test). Data are expressed as mean ± SEM and analysed using a RM two-way ANOVA (A,B), followed by Bonferroni's correction (time and treatment as dependent variables). For single time point behavioural tests, a one-way ANOVA with Bonferroni's correction was used (C–K, n = 8 for vehicle control, n = 8 for the nitroglycerine cephalgia model, n = 8 for the nitroglycerine/sumatriptan group). * indicates a significant difference to the vehicle control (p < 0.05). For detailed p-values of group comparisons, see Table 1.