Mechanism of noradrenaline-induced stimulation of Na-K ATPase activity in the rat brain: implications on REM sleep deprivation-induced increase in brain excitability.

Rapid eye movement (REM) sleep is a unique phenomenon expressed in all higher forms of animals. Its quantity varies in different species and with ageing; it is also affected in several psycho-somatic disorders. Several lines of studies showed that after REM sleep loss, the levels of noradrenaline (NA) increase in the brain. The NA in the brain modulates neuronal Na-K ATPase activity, which helps maintaining the brain excitability status. The detailed mechanism of increase in NA level after REM sleep loss and the effect of NA on stimulation of Na-K ATPase in the neurons have been discussed. The findings have been reviewed and discussed with an aim to understand the role of REM sleep in maintaining brain excitability status.