Therapeutic sleep deprivation and magnesium: Modulators of the GABA/glutamate equilibrium

Total sleep deprivation (TSD) relieves depression. Sleep-EEG and endocrine changes are in accordance with a GABAagonistic or glutamate antagonistic mechanism. We measured the content of GABA, glutamate (Glu) and glutamine (Gln) before and after TSD in four brain regions in six healthy subjects using proton magnetic resonance spectroscopy. The unresolved estimate of GABA, Glu and Gln, as well as GABA and Gln were increased in the pons after 24h of TSD, in line with an increase in GABAergig vs. glutamateric neurotransmission.

Mg is a naturally occurring NMDA receptor antagonist, which is a class of substances showing antidepressant properties. Mg administration in healthy elderly subjects led to an increase in slow wave and spindle activity in the sleep EEG, which is similar to the changes after sleep deprivation. These data support the view that GABA and Gln may play a role in the mechanism of antidepressant pharmacotherapy.