Fig. 3.

Effect of chemical stimulation of vlPAG with microinjection of NMDA, at doses of 0.1, 0.3, and 0.6 nmol, or of physiological saline on the nociceptive threshold. N = 8. *p < 0.001 when compared to the control group (saline); ^#p < 0.001 compared to NMDA at a dose of 0.1 nmol, according to the repeated measures analysis of variance, followed by Duncan’s post hoc test. BL: baseline tail withdrawal test, measured before treatment. X-axis: tail withdrawal response consecutive measurement taken at intervals of 5 min. Y-axis: nociceptive threshold (measured in s). Data were represented as means ± SEM