Q. Function of Adenosine in consciousness?

The adenosine plays a major role in inducing sleep. Injections of adenosine promote sleep and decrease wakefulness. Conversely, adenosine receptor antagonists' caffeine and theophylline are widely used as stimulants to induce vigilance and promote wakefulness.

During wakefulness adenosine accumulates in the extracellular space of the basal forebrain. The increase in extracellular adenosine concentration decreases the activity of the wakefulness-promoting cholinergic neurons in the basal forebrain. When the activity of the wakefulness-active cells decreases sufficiently sleep is initiated. During sleep the extracellular adenosine concentrations decrease, and thus the inhibition of the wakefulness-active cells also decreases allowing the initiation of a new wakefulness period.