Age-related changes in the distribution of Kv1.1 and Kv3.1 in rat cochlear nuclei.
OBJECTIVE
To identify age-related changes in voltage-gated K(+) (Kv) channels that contribute to temporal processing in neurons of the central auditory system, we investigated the distribution of Kv1.1 and Kv3.1 in the auditory brainstem of adult and aged rats.


METHODS
Immunohistochemistry was performed in accordance with the free-floating method described earlier.


RESULTS
Among the auditory nuclei, only the posterior ventral cochlear nucleus (PVCN) showed age-related changes. Kv1.1 immunoreactivity was increased in the octopus cell bodies, while the staining intensity was significantly decreased in the neuropil. Image analysis demonstrated the specific increase in Kv1.1 immunoreactivity in aged cochlear nucleus neurons although the mean density of the entire selection was significantly decreased. In contrast, the number of Kv1.1-immunoreactive neurons was not significantly different between control and aged groups. The immunoreactivity for Kv3.1 was decreased in the octopus cells and neuropil of aged PVCN, which was confirmed by image analysis. The number of Kv3.1-positive cells was also significantly decreased in aged PVCN.


CONCLUSIONS
This study may provide useful data to compare age-related changes in Kv1.1 and Kv3.1 with known physiological properties of auditory neurons.
Jung
Do Kwang
DK
Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Chung-Ang University, 221 Heukseok-Dong, Dongjak-Gu, Seoul 156-756, Korea.
Lee
Sei Young
SY
Kim
Daejin
D
Joo
Kyeung Min
KM
Cha
Choong Ik
CI
Yang
Hoon Shik
HS
Lee
Won Bok
WB
Chung
Yoon Hee
YH
D000367:Age Factors; D000375:Aging; D000818:Animals; D002452:Cell Count / Q000379:methods; D017626:Cochlear Nucleus / Q000166:cytology / Q000378:metabolism*; D003952:Diagnostic Imaging / Q000379:methods; D007150:Immunohistochemistry / Q000379:methods; D051662:Kv1.1 Potassium Channel; D008297:Male; D009474:Neurons / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism*; D024642:Potassium Channels, Voltage-Gated / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D051670:Shaw Potassium Channels
D009479:Neuropeptides; D024642:Potassium Channels, Voltage-Gated; D051670:Shaw Potassium Channels; D051662:Kv1.1 Potassium Channel