Blood and brain magnesium in inbred mice and their correlation with sleep quality

A strong genetic component in the regulation of blood magnesium (Mg) levels has been demonstrated. The regulation and distribution of brain Mg levels, however, have never been assessed. Herein we report on the genetic variati on of peripheral and central Mg levels in six inbred strains of mice. In ad dition, the possible involvement of Mg in sleep regulation was assessed by establishing correlations between Mg and sleep parameters obtained before a nd after a 6-h sleep deprivation. Although genotype strongly determined blo od Mg levels, it did not affect brain Mg, suggesting that central and perip heral Mg are regulated differently. Central Mg displayed a highly structure -specific distribution with frontal cortex having the highest and brain ste m the lowest values. Whereas for the amount and distribution of baseline sl eep only marginal correlations with Mg were found, Mg contents in four of n ine brain structures were highly positively correlated with the length of s low-wave sleep episodes during recovery. This relationship suggests that hi gher levels of Mg in specific brain sites promote sleep quality as part of a recovery process.