Delta-sleep-inducing peptide (DSIP) is a neuropeptide that when infused into the mesodiencephalic ventricle of recipient rabbits induces spindle and delta EEG activity and reduced motor activities.^[1]

Its amino acid sequence is Trp–Ala–Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE). The gene has yet to be found in rabbits, along with any receptors or precursor peptides. However, searches through BLAST have found that it aligns with a hypothetical Amycolatopsis coloradensis protein. This could indicate that DSIP has a bacterial origin