Effects of a Magnesium Deficient Diet on Sleep Organization in Rats

Abstract

The influence of magnesium, one of the most important cations in the vertebrate body, on the sleep-wakefulness cycle and ECoG patterns in chronically implanted rats recorded during the light period over a 6-hour period was investigated. Two groups of rats were studied. Group 1 (6 rats): after a control period of 2 weeks, the rats were maintained for 9 weeks on a Mg²⁺-deficient diet. Group 2 (5 rats): after a control period of 2 weeks, the rats were maintained for 7 weeks on a Mg²⁺-deficient diet followed by 4 weeks on a normal diet (recovery period: weeks 8–11). Mg²⁺-deficient diet for 9 weeks induced sleep and ECoG time-dependent alterations. After 6–7 weeks on a Mg²⁺-defi-cient diet (n = 11) sleep analysis showed a significant increase of wakefulness (+50%) at the expense of slow wave sleep (–24%) but paradoxical sleep was not significantly modified. After 9 weeks of a Mg²⁺ deficient diet, sleep was desorganized: light sleep and polyspikes occurred indicating an increase in neuronal excitability. When Mg²⁺ was reintroduced in food and water, sleep organization and ECoG recordings were restored to their original patterns. Our findings which are in line with previous clinical and pharmacological observations provide conclusive arguments for the neuroprotective effect of magnesium ions in neurologic disorders and epileptiform activity. Mg²⁺ deficiency induces ECoG alterations in the rat which bear some similarities with those seen in neurogenic spasmophilic syndromes in man.

Oral Mg2+ Supplementation Reverses Age-Related Neuroendocrine and Sleep EEG Changes in Humans

“…Our results on the effect of Mg 2+ at the sleep EEG agree with the observation of a decrease of SWS in rats with Mg 2+ deficiency [23] and reports of a sleep-stabilising effect of Mg 2+ in patients before surgery [81]. A highly positive correlation with the length Original Paper of SWS and the levels of Mg 2+ in specific brain areas was observed in mice [18].…”

“…Also, the changes in the sleep EEG occurring during ageing bear some similarities to those in Mg 2+ deficiency. Mg 2+ deficits lead to sleep disturbances with increased wakefulness at the expense of SWS [23] or a predominance of active waking and a decrease in total sleep time [64] in rats. On the other hand, there have also been reports on a sleep-stabilising effect of Mg 2+ .…”

Magnesium Intake and Sleep Disorder Symptoms: Findings from the Jiangsu Nutrition Study of Chinese Adults at Five-Year Follow-Up

“…The inverse association between magnesium consumption and falling asleep is biologically plausible. In animal studies, researchers have demonstrated that magnesium deficiency could affect normal sleep-wake rhythm by increasing periods of wakefulness and reducing slow wave sleep in rats, and such effect was recovered when reintroducing magnesium in their diet [ 22 ]. Magnesium deficiency has been suggested to related to muscle cramps, which can contribute to a poor sleep and consequent sleepiness the day after.…”

Mg 2+ reduces ACTH secretion and enhances spindle power without changing delta power during sleep in men - possible therapeutic implications

“…Mg 2+ deÞciency in the rat leads to sleep disturbances, with a predominance of active waking and a decrease in total sleep time (Poenaru et al 1984) or an increase in wakefulness at the expense of slow wave sleep (SWS) and a disorganization of sleep in rats (Depoortere et al 1993). Support for a sleep-stabilizing e¤ect of Mg 2+ comes from the Þnding that IV administration of Mg 2+ before surgery led to a signiÞcantly better quality of sleep in a double-blind trial on surgical patients (Tramer et al 1996).…”