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Figure 6 | Molecular Pain

Figure 6

From: A simplified up-down method (SUDO) for measuring mechanical nociception in rodents using von Frey filaments

Figure 6

Flowchart summarizing mechanosensitivity testing protocols of Chaplan et al. and SUDO. In the method of Chaplan et al. [3], the threshold is considered to have been reached the first time that the response of the animal to a von Frey filament is different from the previous trial, after which four additional von Frey presentations are conducted in an up-down manner. At the end of the trial the paw withdrawal estimate (PWT) is calculated by taking the value of the final filament used and adding an adjustment factor derived from the response pattern using the calculations of Dixon [5]. In SUDO, only five von Frey filament presentations are done in each test and the PWT is estimated directly from the response to the final filament by incorporating a fixed adjustment factor based on the response to the fifth filament. See text for additional details.

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