MT2 melatonin receptor immunoreactivity in neurons is very high in the aged hippocampal formation in gerbils.
Melatonin exerts many physiological functions via its G protein-coupled receptors. In the present study, we investigated age-related changes in MT2 melatonin receptor immunoreactivity and its levels in the gerbil hippocampus during normal aging. In the postnatal month 1 (PM 1) group, MT2 immunoreaction was well observed in neurons in all subregions of the gerbil hippocampus. In the PM 3 and 6 groups, MT2 immunoreactivity in neurons was decreased compared to that in the PM 1 group. Thereafter, MT2 immunoreactivity in neurons was increased. In the PM 18 and 24 groups, MT2 immunoreactivity in neurons was strong in all subregions of the gerbil hippocampus. In addition, the number of MT2 immunoreactive cells was lowest at PM 3 and highest at PM 24. From western blot analysis, age-dependent change pattern in MT2 level in the gerbil hippocampus was similar to the immunohistochemical result. These results indicate that MT2 immunoreactivity and levels are altered in the gerbil hippocampus during normal aging; lowest at young adult stage and highest at aged stage.
Lee
Choong Hyun
CH
Department of Anatomy and Neurobiology, and Institute of Neurodegeneration and Neuroregeneration, College of Medicine, Hallym University, Chuncheon, 200-702, South Korea.
Choi
Jung Hoon
JH
Yoo
Ki-Yeon
KY
Park
Ok Kyu
OK
Hwang
In Koo
IK
You
Sang Guan
SG
Lee
Boo-Yong
BY
Kang
Il-Jun
IJ
Won
Moo-Ho
MH
D000375:Aging / Q000502:physiology*; D000818:Animals; D005849:Gerbillinae; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism; D008297:Male; D008550:Melatonin / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D044123:Receptor, Melatonin, MT2 / Q000378:metabolism*
D044123:Receptor, Melatonin, MT2; D008550:Melatonin