Table 1. Method for determining value of the PWMT.

Note: A 10 graded series of von Frey monofilaments (vF) weighing at different intensities ranging from 19.6 mN to 588 mN were used (see the above Table 1). The measurement of the PWMT was started from the lowest to the higher intensity of the vF, and stopped with the endpoint readout at a given intensity that could induce 50-60% of paw withdrawal reflex to 10 stimuli applied to each paw pad. Table 1 shows an example of results from measurements of baseline values in PWMT (PWMT_baseline, mN) in six animals (#1-6). For details, the animal #1 did not respond to the vF stimuli at intensities of 19.6 mN, 39.2 mN, 58.8 mN and 78.4 mN at all when receiving 10 stroking stimuli (shown as 0/10), while it responded with one paw withdrawal to 10 times of 98.0 mNvF stimuli (1/10), and with three paw withdrawals to those of 147 mN (3/10), and with five and six paw withdrawals to those of 255 mN (5/10) and 294 mN (6/10), thus the PWMT_baseline value could be determined as 255 mN (green rectangled). The green rectangled numbers indicate the readout PWMT for a paw pad of 4 animals (1-4#), while the red rectangled ones indicate extreme bias of either hypersensitive (5#) or hyposensitive (6#) which should be excluded from the experiment.