Young A M, Key B J
Neuropharmacology. 1984 Nov;23(11):1347-50. doi: 10.1016/0028-3908(84)90058-3.
The somnogenic properties of delta sleep-inducing peptide (DSIP) were investigated using electroencephalographic criteria. The peptide caused a significant increase in both REM and non-REM sleep at the expense of waking when injected into the lateral ventricle of the rat brain in four doses of 5 micrograms during the dark (waking) phase of the light/dark cycle. Furthermore this sleep promoting effect was blocked by pre-treatment with the opiate antagonist naloxone at a dose level (0.1 mg/Kg s.c.) considered selective for mu-receptors.