Effect of Mg2+ on Neural Activitiy
Materials Science Laboratory
It is well known that magnesium ion (Mg2+) plays an important role in biological functions, similar to that of calcium ion (Ca2+). It would be useful to understand the effect of Mg2+ on neural functions in relation to controlling neural activity. However, the relationship between Mg2+ and neural functions has not been well understood. Although recent studies indicate that an Mg2+ deficient diet has significant health effects, few reports have studied the effect of Mg2+ on neural activity . Here we have investigated the effect of low concentrations of extracellular Mg2+ on membrane potential using flow cytometry, and on the intracellular Ca2+ concentration using a confocal laser microscope.
Figure 1 shows the Mg2+ dependence on the membrane potential of cortical neurons. Oxyonol dye DiBAC4(3) was used for the measurements. The results indicate that a low Mg2+ concentration depolarizes the membrane potential depending on the reduction in the extracelluar Mg2+ concentration below 2 mM [2, 3]. The developmental effect of Mg2+ was significant at 12 days in vitro (DIV), and could be observed at a concentration of less than 0.7 mM (Fig. 2) [2, 3].
The same type of Mg2+ dependence was observed in hippocampal neurons. However, the responses of cortical and hippocampal neurons to a low Mg2+ concentration differed during the developmental period. The results indicate that hippocampal neurons are more sensitive to Mg2+ than cortical neurons. This may originate in the difference in the receptor distribution in those regions . Further investigation is needed to understand the mechanisms of the Mg2+ effect on neural activity.
 K.Torimitsu, N. Kasai, and Y. Furukawa, Clin. Calcium 14 (2004) 26.
 Y. Furukawa and K. Torimitsu, JJSMgR 27 (2008) 75.
 Y. Furukawa, N. Kasai, and K. Torimitsu, Magnes. Res. 22 (2009) 174S.
Fig..1. Magnesium dependence of membrane potential
in cortical neurons.
Fig..2. Developmental effect of magnesium on
intracellular Ca2+ concentrations.
[back] [Top] [Next]