Fig. 1. Pronociceptive effects of remifentanil administered at different infusion doses. For the Hargreaves ( A ) and von Frey ( B ) tests, results are expressed as mean value of the area above the time–effect curves (AACs) of nociceptive thresholds over time (2, 4, 7, and 10 days) after remifentanil infusion. The number of animals in the saline group was n = 7, and those in the remifentanil groups were as follows: dose of 0.66 μg · kg−1· min−1(n = 8), 1.33 μg · kg−1· min−1(n = 8), 2.66 μg · kg−1· min−1(n = 7), and 3.33 μg · kg−1· min−1(n = 9). Values were normalized to the control group (saline). In this figure, each graph includes the equation corresponding to the represented linear regression, where y is the overall effect and x is the infused dose. The Pearson coefficient, R 2, is included as a measure of the relation between both variables.
