title: Nociceptive responses and immunohistochemical changes in the rat brain under gravity stress.
abstract: It is well known that exposure to various stresses leads to pain suppression in animals. However, there is no report about the effects of gravitational alteration to serve as a kind of stress. The purpose of the present study is to clarify the effect of hypergravity (2 G) on the nociceptive responses and histochemical changes in rats. We examined the level of the threshold of withdrawal reflex against the noxious [correction of noxicious] stimulation in rats that were exposed to 2 G. Data show that the 2 G exposure elevates the nociceptive threshold. We have demonstrated for the first time that gravity change induces analgesic effects on rats in concomitant with c-fos induction in the arcuate, and paraventricular nuclei of rat hypothalamus. Gravity change acts as a kind of stress in rats.
authors.affiliation: Dept. of Biochemistry, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kumei
authors.forename: K
authors.initials: K
authors.lastname: Toda
authors.forename: Y
authors.initials: Y
authors.lastname: Kawauchi
authors.forename: R
authors.initials: R
authors.lastname: Shimokawa
authors.forename: H
authors.initials: H
authors.lastname: Shimokawa
authors.forename: K
authors.initials: K
authors.lastname: Makita
mesh_terms: D000698:Analgesia; D000818:Animals; D018471:Hypergravity; D007150:Immunohistochemistry; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological
chemical_list: D016760:Proto-Oncogene Proteins c-fos