Intermittent hypoxia modulates Na+ channel expression in developing mouse brain

Because our previous work showed that intermittent hypoxia alters neuronal excitability and Na+ current density, we examined in this work the effect of intermittent hypoxia on Na+ channel subtypes using 3H-saxitoxin (3H-STX) autoradiography and immunoblotting. Mice were exposed to intermittent hypoxia for 2 or 4 weeks from postnatal day 2 or 3. A 2-week intermittent hypoxia reduced cerebral STX binding density with significant decrease in Nav1.2 in the rostral and Nav1.1 in the caudal regions. In contrast, a 4-week intermittent hypoxia tended to increase STX binding density in most brain regions. Our data suggest that intermittent hypoxia differentially regulates plasma membrane Na+ channels in the developing brain, depending on duration of intermittent hypoxia.