Electrical Stimulation of Large Myelinated Afferents Inhibits Responses of Rat Spinal Dorsal Horn Neurons to Noxious and Innocuous Cutaneous Stimulation
{"title":"Electrical Stimulation of Large Myelinated Afferents Inhibits Responses of Rat Spinal Dorsal Horn Neurons to Noxious and Innocuous Cutaneous Stimulation","authors":"M. Tsuruoka, Yong-ning Wang, Y. Matsui","doi":"10.11516/DENTALMEDRES1981.13.31","DOIUrl":null,"url":null,"abstract":"The inhibitory effects of electrical stimulation of large myelinated afferents on_ spinal dorsal horn neurons were investigated. In rats anesthetized with thiamylal sodium,_ responses of 153 dorsal horn neurons to noxious heating or innocuous mechanical stimulation_ (light brushing) of the tail were recorded from the sacral and coccygeal levels of the spinal cord_ by extracellular microelectrodes. Of these neurons, 45 were low-threshold mechanoreceptive_ (LTM), 47 were nociceptive-specific (NS), and 61 were wide-dynamic-range (WDR) neurons_. In 22.2% of the LTM neurons, responses to innocuous mechanical stimulation were inhibited_ by electrical stimulation of large myelinated afferents applied to the ipsilateral hindlimb for_ 5 min. This conditioning stimulation (large myelinated afferent stimulation, LMAS) also inhibited noxious heat responses in 19.2% of the NS neurons. The inhibitory effect of LMAS_ on WDR neurons was nonselective in that both responses to light brushing and noxious heating were inhibited. Of the WDR neurons, 27.3 % were inhibited by LMAS. These results_ indicate that inhibition produced by LMAS is exerted on all 3 classes of spinal dorsal horn neu_ rons.","PeriodicalId":77624,"journal":{"name":"Showa Shigakkai zasshi = The Journal of Showa University Dental Society","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1993-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Showa Shigakkai zasshi = The Journal of Showa University Dental Society","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.11516/DENTALMEDRES1981.13.31","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 1
Abstract
The inhibitory effects of electrical stimulation of large myelinated afferents on_ spinal dorsal horn neurons were investigated. In rats anesthetized with thiamylal sodium,_ responses of 153 dorsal horn neurons to noxious heating or innocuous mechanical stimulation_ (light brushing) of the tail were recorded from the sacral and coccygeal levels of the spinal cord_ by extracellular microelectrodes. Of these neurons, 45 were low-threshold mechanoreceptive_ (LTM), 47 were nociceptive-specific (NS), and 61 were wide-dynamic-range (WDR) neurons_. In 22.2% of the LTM neurons, responses to innocuous mechanical stimulation were inhibited_ by electrical stimulation of large myelinated afferents applied to the ipsilateral hindlimb for_ 5 min. This conditioning stimulation (large myelinated afferent stimulation, LMAS) also inhibited noxious heat responses in 19.2% of the NS neurons. The inhibitory effect of LMAS_ on WDR neurons was nonselective in that both responses to light brushing and noxious heating were inhibited. Of the WDR neurons, 27.3 % were inhibited by LMAS. These results_ indicate that inhibition produced by LMAS is exerted on all 3 classes of spinal dorsal horn neu_ rons.