Fig. 5

Effects of activation of α-adrenoceptors on changes in the hemodynamics of the masseter muscle and on SABP evoked by AN stimulation after CST sectioning during high spontaneous activity in the CST. a, b Typical examples of changes in the MBF and VC in the left masseter muscle and SABP evoked by left AN stimulation (AN stim.; 20 s, 10 V, 20 Hz, 2-ms) (at black horizontal bars) at 10 min after left CST sectioning (Control CSTs), in combination with intravenous administration for 10 min (0.1 ml/min) of α₂-adrenoceptor agonist clonidine (2–10 μg/ml), clonidine (10 μg/ml) and yohimbine (0.5 mg/ml) or propranolol (1 mg/ml) applied together, and 30 min after the injection (a), and in combination with administration of α₁-adrenoceptor agonist phenylephrine (2–10 μg/ml) (b). The white trace shows the mean VC for the various data. c Mean data ± SEM of the changes (black bars) in the left MBF (top) and masseter muscle VC (bottom) evoked by AN stimulation at 10 min after CST sectioning for the various treatments (n = 6 in each group). Presence (+) or absence (−) of treatment is indicated under the bars. Statistical significance of the differences from the control before the drug injections determined by ANOVA, followed by a post hoc test (Fisher’s PLSD). *P < 0.001 vs. control. Significant differences between sets of data (P < 0.05, P < 0.001) are indicated above the appropriate square bracket (ANOVA followed by a contrast test)