Wakefulness, non-rapid-eye-movement sleep (NREMS), and rapid-eye-movement sleep (REMS) after intracerebroventricular (icv) administration of 0.2, 1 and 5 µg ghrelin at light onset in mice.

<p>Open symbols: isotonic saline injection, solid symbols: ghrelin injection. Data were calculated in 1-h time blocks. Arrow: time of the injections. Asterisks denote significant differences between baseline and treatment days (post hoc paired t-test).