Bright light as an inhibitor of adenosine transport

The administration of bright light rapidly improves subjective alertness and is likely to have direct effects on the activity of neurons in the suprachiasmatic nucleus (SCN). Bright light may enhance wakefulness by interrupting the increase in extracellular adenosine concentration with brain metabolism during the day. Exposure to bright light is hypothesized to induce the inhibition of adenosine transport, promoting both subjective alertness and activation measured objectively, and to activate the cholinergic neurons of the reticular system and those using gamma-aminobutyric acid as a neurotransmitter in the SCN.