Effect of Mg2+ on neural activity of rat cortical and hippocampal neurons in vitro.
Mg2+ plays an important role in biological functions, similar to that of Ca2+. In terms of neural activity, it is well known that Mg2+ blocks the NMDA receptor. However, the relationship between Mg2+ and neural function has not been well understood. We have investigated the effect of low extracellular Mg2+ concentration ([Mg2+]o) on neural activity in rat cortical and hippocampal neurons by using microelectrode array (MEA) measurements and glutamate measurements, with an enzyme modified MEA-based multi-array sensor. In this study, we investigated the effects of low [Mg2+]o on intracellular Ca2+ concentration ([Ca2+]i) using a confocal laser microscope and a flow cytometer with a fluorescence probe. The results indicate that low [Mg2+]o has an effect on neural activity. The responses of cortical and hippocampal neurons to low [Mg2+]o differed in the developmental period. The results suggest that hippocampal neurons are more sensitive to [Mg2+ than cortical neurons. The glutamate receptor distributions in the cortex and hippocampus may be different. Further investigation is required to understand the mechanisms of the Mg2+ effect on neural activity.
NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan. yuri@will.brl.ntt.co.jp
Yuriko
Y
Furukawa
Nahoko
N
Kasai
Keiichi
K
Torimitsu
D000818:Animals; D002118:Calcium / Q000097:blood; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects*; D005434:Flow Cytometry; D006624:Hippocampus / Q000187:drug effects*; D008274:Magnesium / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects*; D018696:Neuroprotective Agents / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
D018696:Neuroprotective Agents; D008274:Magnesium; D002118:Calcium