Erami Elaheh, Azhdari-Zarmehri Hassan, Imoto Keiji, Furue Hidemasa
Department of Nursing, Faculty of Nursing and Midwifery, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran.
Department of Information Physiology, National Institute for Physiological Sciences, Okazaki, Japan.
Basic Clin Neurosci. 2017 Jan;8(1):37-42. doi: 10.15412/J.BCN.03080105.
Glabrous skin and hairy skin are innervated by different types of noxious fibers. However, the different nociceptive behaviors induced by formalin, a commonly used model of acute inflammatory pain, have not yet been systematically examined in the glabrous and hairy skin.
In this study, we compared nociceptive behaviors induced by formalin injections (2%, 4%, and 8%) into either glabrous skin (plantar surface) of the hind paw or hairy skin of the hind limb in adult rats.
A typical biphasic nociceptive response was seen after formalin injection into the plantar surface of the hind paw. A brief interphase separates the first and second phases where nociceptive behaviors were barely spotted. However, following subcutaneous injection into the hairy skin nociceptive behaviors were only seen after 10 minutes of formalin injection, which correlates in time with the second phase of the formalin response. First phase nociceptive behaviors were never seen with hairy skin injection, even following multiple injections of formalin.
These data suggest that nociceptive behaviors and spinal responses induced by formalin injections to glabrous and hairy skin areas are different, and that the first and second phases may be mediated through different noxious afferent fibers.
无毛皮肤和有毛皮肤由不同类型的伤害性纤维支配。然而，福尔马林（一种常用的急性炎症性疼痛模型）在无毛皮肤和有毛皮肤中所引发的不同伤害感受行为，尚未得到系统研究。
在本研究中，我们比较了将福尔马林（2%、4%和8%）注射到成年大鼠后爪无毛皮肤（足底表面）或后肢有毛皮肤中所引发的伤害感受行为。
将福尔马林注射到后爪足底表面后，观察到典型的双相伤害感受反应。第一阶段和第二阶段之间有一个短暂的间期，在此期间几乎观察不到伤害感受行为。然而，在将福尔马林皮下注射到有毛皮肤后，仅在注射10分钟后才观察到伤害感受行为，这在时间上与福尔马林反应的第二阶段相关。即使多次注射福尔马林，在有毛皮肤注射时也从未观察到第一阶段的伤害感受行为。
这些数据表明，福尔马林注射到无毛和有毛皮肤区域所引发的伤害感受行为和脊髓反应是不同的，并且第一阶段和第二阶段可能是通过不同的伤害性传入纤维介导的。
