Chronic lithium enhances hippocampal long-term potentiation, but not neurogenesis, in the aged rat dentate gyrus.
We investigated the hippocampal long-term potentiation (LTP), neurogenesis, and the activation of signaling molecules in the 20-month-old aged rats following chronic lithium treatment. Chronic lithium treatment produced a significant 79% increase in the numbers of BrdU(+) cells after treatment completion in the dentate gyrus (DG). Both LTP obtained from slices perfused with artificial cerebrospinal fluid (ACSF-LTP), and LTP recorded in the presence of bicuculline (bicuculline-LTP) were significantly greater in the lithium group than in the saline controls. Our results show that as with young rats, chronic lithium can substantially increase LTP and the number of BrdU(+) cells in the aged rats. However, neurogenesis, assessed by colocalization of NeuN and BrdU, was not detected in the aged rat DG subjected to chronic lithium treatment. Therefore, it is concluded that the increase in LTP and the number of BrdU(+) cells might not be associated with increases in neurogenesis in the granule cell layer of the DG. Lithium might has a beneficial effects through other signaling pathways in the aged brain.
Yu
In Tag
IT
Department of Biochemistry, Hanyang University College of Medicine, 17 Haengdang-dong, Sungdong-gu, Seoul 133-791, Republic of Korea.
Kim
Jin Seuk
JS
Lee
Sang-Hun
SH
Lee
Yong-Sung
YS
Son
Hyeon
H
D000375:Aging; D000818:Animals; D001973:Bromodeoxyuridine / Q000032:analysis; D002478:Cells, Cultured; D018891:Dentate Gyrus / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D007700:Kinetics; D008094:Lithium / Q000008:administration & dosage / Q000494:pharmacology*; D017774:Long-Term Potentiation / Q000187:drug effects*; D008297:Male; D009474:Neurons / Q000737:chemistry / Q000166:cytology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013234:Stem Cells / Q000502:physiology
D008094:Lithium; D001973:Bromodeoxyuridine