The “Plantar Test” Apparatus (Ugo Basile Biological Apparatus), a Controlled Infrared Noxious Radiant Heat Stimulus for Precise Withdrawal Latency Measurement in the Rat, as a Tool for Humans?

Abstract

In the present study, we precisely and automatically measured the withdrawal latency to noxious radiant heat application in unrestrained male rats and in human subjects of both sexes, by means of the "plantar test" apparatus (Ugo Basile Biological Apparatus). The infrared light stimulus of this tool was applied underneath the hindpaws of rats and the middle fingers of human subjects. With one right and one left stimulation every 10 min, we observed a decrease in latency over a 40-min testing period in rats; the latency reached a mean value of 5.08 +/- 0.25 sec after 40 min with a 36-W stimulus, which corresponded to 46.5 degrees C. In pilot experiments, also performed on rats, we showed that the opiate morphine (10 mg/kg, i.p.) produced remarkable increases of the withdrawal latency only in "naive" animals (i.e., ones that had never experienced the plantar test stimulus) and not in animals "habituated" to it. Among humans, we noted gender differences, such as less sensitivity to the infrared noxious radiant heat for women, particularly during the menstrual period. A difference from rats was that there was no significant latency modification along the 40-min testing period for either women or men, with a mean latency of 5.61 +/- 0.18 sec (47.5 degrees C) for the women and 4.39 +/- 0.10 sec (45.5 degrees C) for the men. These data confirm the reliability of the plantar test in rats, and demonstrate the possible use of an infrared source in human subjects as a noxious heat stimulus; the withdrawal reaction to this stimulus is emphasized as a good index of nociception in humans.

The antinociceptive efficacy of buprenorphine administered through the drinking water of rats

“…However, at the same time, the treated rats had significantly longer paw withdrawal latency times than control rats. Thus, the duration of action of buprenorphine was at least 8 h. Moreover, repetitive exposure to noxious heat can produce a decrease in paw withdrawal latency time, possibly as a result of a central and/or peripheral hyperalgesic response (Montagne-Clavel & Oliveras 1996). In our study, hyperalgesia was induced, as evidenced by decreasing paw withdrawal latency times in the control group, during the testing period.…”

Tail-flick test response in 3×Tg-AD mice at early and advanced stages of disease

“…Our results contribute to the knowledge of how stress is known to influence nociceptive perceptions and responses [27,28] since this analgesic modulatory effect is taken under consideration in the protocols such as the plantar test [29]. Besides, the analgesic actions of opiate morphine results in remarkable increases of the withdrawal latency only in naive animals (i.e., ones that had never experienced the plantar test stimulus) and not in animals 'habituated' to it [27].…”

Characterization of hind paw licking and lifting to noxious radiant heat in the rat with and without chronic inflammation

“…Important factors which influence the validity of this thermal sensory pain test are stimulus intensity, glass floor temperature (Dirig et al, 1997;Galbraith et al, 1993), rate of skin heating (Yeomans and Proudfit, 1996) and the source of radiant heat (Montagne-Clavel and Oliveras, 1996) The thermal radiant heat test has several advantages over other nociceptive assays-the thermal sensory test can be performed in un-restrained and un-anesthetized animals, and constant stimulus intensity can be applied. In a given set of experimental conditions, successive application of noxious radiant heat to the plantar surface of the hind paw may make the animal just move (twitch) or lift away the paw to avoid the painful stimulus, or may exhibit more intense pain behavior like paw licking.…”