Arachidonic acid enhances intracellular calcium levels in dentate gyrus, but not CA1, in aged rat.
The effect of dietary supplementation with polyunsaturated fatty acids (PUFAs) on long-term potentiation (LTP) and calcium mobilization in hippocampal slices from aged rats was assessed. LTP magnitude was significantly greater in PUFA-supplemented animals compared to age-matched controls (OCs). LTP did not differ among PUFA-supplemented groups. Calcium mobilization was estimated following membrane depolarization and selective activation of NMDA receptors. The resting level of [Ca2+](i) was slightly elevated in aged preparations compared to young controls (YCs). The transient increase in [Ca2+](i) in CA1 was significantly smaller in aged rats than in YC. The maximum increase in [Ca2+](i) in the CA1 and dentate gyrus (DG) did not differ among aged groups. The maximum increase in [Ca2+](i) and the calcium buffering ability were significantly greater in YC than in the aged rats. Selective activation of NMDA receptors induced regional differences in Ca2+ elevation. In the DG, Ca2+ elevation in OA was comparable to that in YC, and significantly higher than that in OC, suggesting that long-term arachidonic acid supplementation rescues the reduced neurogenesis in the DG. The decay in the depolarization and NMDA-induced increase in [Ca2+](i) was prolonged in aged CA1 and DG.
Graduate School of High-Technology for Human Welfare, Tokai University, Numazu 410-0321, Shizuoka, Japan.
Yasuto
Y
Kashiyae
Masanori
M
Kontani
Hiroshi
H
Kawashima
Yoshinobu
Y
Kiso
Yoshihisa
Y
Kudo
Manabu
M
Sakakibara
D000375:Aging / Q000378:metabolism*; D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002462:Cell Membrane / Q000502:physiology; D018891:Dentate Gyrus / Q000187:drug effects / Q000378:metabolism; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D006706:Homeostasis; D042541:Intracellular Space / Q000378:metabolism*; D017774:Long-Term Potentiation; D008297:Male; D016202:N-Methylaspartate / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344; D016194:Receptors, N-Methyl-D-Aspartate / Q000819:agonists
D016194:Receptors, N-Methyl-D-Aspartate; D016718:Arachidonic Acid; D016202:N-Methylaspartate; D002118:Calcium