title: Serotonin release in the central nucleus of the amygdala in response to noxious and innocuous cutaneous stimulation in anesthetized rats.
abstract: We investigated the effect of noxious (pinching) and innocuous (stroking) stimulation of skin on serotonin (5-HT) release in the central nucleus of the amygdala (CeA) in anesthetized rats. 5-HT in the CeA was collected by microdialysis methods. Dialysate output from consecutive 10-min periods was injected into a high-performance liquid chromatograph and 5-HT was measured with an electrochemical detector. Bilateral pinching of the back for 10 min increased 5-HT release significantly; 5-HT release was also increased with stimulation of the forelimb or hindlimb. In contrast, stroking of these areas decreased 5-HT release significantly. Furthermore, simultaneous stroking and pinching produced no change in the 5-HT release. In conclusion, the present study demonstrates that 5-HT release in the CeA is regulated by somatic afferent stimulation in a modality-dependent manner, and that innocuous stimulation can dampen the change in 5-HT release that occurs in response to noxious stimulation.
authors.affiliation: Division of Physical Therapy, Graduate School of Health and Welfare Sciences, International University of Health and Welfare, Otawara, Tochigi, 324-8501, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Tokunaga
authors.affiliation: Division of Physical Therapy, Graduate School of Health and Welfare Sciences, International University of Health and Welfare, Otawara, Tochigi, 324-8501, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Shimoju
authors.affiliation: Division of Physical Therapy, Graduate School of Health and Welfare Sciences, International University of Health and Welfare, Otawara, Tochigi, 324-8501, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Takagi
authors.affiliation: Laboratory of Veterinary Anatomy, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan.
authors.forename: Hideshi
authors.initials: H
authors.lastname: Shibata
authors.affiliation: Division of Physical Therapy, Graduate School of Health and Welfare Sciences, International University of Health and Welfare, Otawara, Tochigi, 324-8501, Japan. mieko-ku@iuhw.ac.jp.|Center for Medical Science, International University of Health and Welfare, 2600-1 Kitakanemaru, Otawara, Tochigi, 324-8501, Japan. mieko-ku@iuhw.ac.jp.|Department of Pharmaceutical Sciences, International University of Health and Welfare, Otawara, Tochigi, 324-8501, Japan. mieko-ku@iuhw.ac.jp.
authors.forename: Mieko
authors.initials: M
authors.lastname: Kurosawa
mesh_terms: D000818:Animals; D066274:Central Amygdaloid Nucleus / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D008297:Male; D017551:Microdialysis; D010146:Pain / Q000378:metabolism*; D010812:Physical Stimulation; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism*; D012867:Skin
chemical_list: D012701:Serotonin
keywords: 5-HT; Central nucleus of the amygdala; Microdialysis; Pinching; Somatic afferent stimulation; Stroking