Developmental distribution of vestibular nuclear neurons responsive to different speeds of horizontal translation.
To examine whether subgroups of vestibular nuclear neurons encode different frequency oscillation of horizontal linear motion, Fos immunohistochemistry was used to document neuronal subpopulations that were functionally activated by such otolithic stimulations. Conscious rats at P7, P14 and adult were subjected to sinusoidal linear acceleration along the transverse axis on the horizontal plane. Labyrinthectomized and/or stationary controls showed only sporadically scattered Fos-labeled neurons in the vestibular nuclei, confirming otolithic origin of c-fos expression. In each age group, Fos-labeled neurons responsive to high frequency stimulation (>1.5 Hz) were clustered in the lateral region of the medial vestibular nucleus while those to low frequency stimulation (0.5-1.0 Hz) were found in the medial portion of the medial vestibular nucleus. The number of these neurons increased with age. No apparent frequency-related distribution pattern of Fos-labeled neurons was observed in other vestibular nuclei and subgroups. Our findings therefore reveal subpopulations of central vestibular neurons responsive to different stimulus frequencies that correspond to head motions ranging from tilt to translation.
Ma
Chun-Wai
CW
Department of Physiology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
Lai
Chun-Hong
CH
Lai
Suk-King
SK
Tse
Yiu-Chung
YC
Yung
Ken K L
KK
Shum
Daisy K Y
DK
Chan
Ying-Shing
YS
D000054:Acceleration; D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D018466:Gravity Sensing / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000145:classification / Q000502:physiology*; D016761:Oncogene Proteins v-fos / Q000378:metabolism; D010315:Particle Accelerators; D051381:Rats; D017207:Rats, Sprague-Dawley; D014726:Vestibular Nuclei / Q000166:cytology* / Q000254:growth & development*
D016761:Oncogene Proteins v-fos