title: Chewing suppresses the stress-induced increase in the number of pERK-immunoreactive cells in the periaqueductal grey.
abstract: We investigated the effects of chewing under immobilization stress on the periaqueductal gray (PAG) matter using phosphorylated extracellular signal-regulated kinase (pERK) as a marker of responding cells. Immobilization stress increased pERK-immunoreactive cells in the PAG. Among four subdivisions of the PAG, the increase of immunoreactive cells was remarkable in the dorsolateral and ventrolateral subdivisions. However, increase of pERK-immunoreactive cells by the immobilization stress was not so evident in the dorsomedial and lateral subdivisions. The chewing under immobilization stress prevented the stress-induced increase of pERK-immunoreactive cells in the dorsolateral and ventrolateral subdivisions with statistical significances (p<0.05). Again, chewing effects on pERK-immunoreactive cells were not visible in the dorsomedial and lateral subdivisions. These results suggest that the chewing alleviates the PAG (dorsolateral and ventrolateral subdivisions) responses to stress.
authors.affiliation: Department of Oral Science, Division of Brain Functions and Neuroscience, Kanagawa Dental University, Yokosuka, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Oral Science, Division of Orthodontics, Kanagawa Dental University, Yokosuka, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Narimatsu
authors.affiliation: Department of Electronics and Bioinformatics, School of Science and Technology, Meiji University, Kawasaki, Japan.
authors.forename: Yumie
authors.initials: Y
authors.lastname: Ono
authors.affiliation: Department of Oral Surgery, Jichi Medical University, Shimotsuke, Japan.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Sasaguri
authors.affiliation: Nittai Jyusei Medical College for Judo Therapeutics, Tokyo, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Onozuka
authors.affiliation: Department of Oral Science, Division of Orthodontics, Kanagawa Dental University, Yokosuka, Japan.
authors.forename: Toshitsugu
authors.initials: T
authors.lastname: Kawata
authors.affiliation: Department of Oral Science, Division of Brain Functions and Neuroscience, Kanagawa Dental University, Yokosuka, Japan. Electronic address: t.yamamoto@kdu.ac.jp.
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D000818:Animals; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D008297:Male; D008409:Mastication; D010487:Periaqueductal Gray / Q000201:enzymology*; D010766:Phosphorylation; D017207:Rats, Sprague-Dawley; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000201:enzymology* / Q000503:physiopathology
chemical_list: D048049:Extracellular Signal-Regulated MAP Kinases
keywords: Chewing; Immobilization stress; Periaqueductal gray; Phosphorylated kinase; Rat