Decreased Fos protein expression in rat caudal vestibular nucleus is associated with motion sickness habituation.
We investigated the temporal change of Fos protein expression in the caudal vestibular nucleus of rats exposed to daily 2-h Ferris-wheel like (FWL) rotation. Repeated rotation (2h daily for 14 consecutive days) caused an initial increase in defecation, followed by a gradual decline back to the baseline level after 8 rotation sessions. Unlike defecation, the Kaolin consumption of rats showed a bitonic function during the daily rotation sessions (2h daily for 33 consecutive days) and finally recovered to the baseline after about 31 sessions. Immunohistochemistry study revealed increased Fos immunolabeled (Fos-LI) neurons in the medial vestibular nucleus and spinal vestibular nucleus during the initial 7 rotation sessions, and it decreased to the baseline level after 10 rotation sessions. There was a strong linear relationship between the amount of Fos-LI neurons and rat defecation level throughout the whole rotation sessions. These results suggest that the change of neuronal plasticity in the caudal vestibular nucleus might contribute to attenuation of gastrointestinal symptoms during motion sickness habituation process.
Cai
Yi-Ling
YL
Department of Military Hygiene, Faculty of Naval Medicine, Second Military Medical University, 800 Xiang Ying Road, Shanghai 200433, PR China. yilingcai1@sohu.com
Wang
Jun-Qin
JQ
Chen
Xin-Min
XM
Li
Hong-Xia
HX
Li
Min
M
Guo
Jun-Sheng
JS
D000818:Animals; D003672:Defecation; D006185:Habituation, Psychophysiologic; D008297:Male; D009039:Motion Perception; D009041:Motion Sickness / Q000378:metabolism / Q000503:physiopathology / Q000523:psychology*; D009474:Neurons / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012399:Rotation; D014726:Vestibular Nuclei / Q000378:metabolism*
D016760:Proto-Oncogene Proteins c-fos