SIFamide in the Brain of the Sphinx Moth, Manduca Sexta

SIFamides form a group of highly conserved neuropeptides in insects, crustaceans, and chelicerates. Beyond their biochemical commonalities, the neuroanatomical distribution of SIFamide in the insect nervous system also shows a remarkable degree of conservation. Thus, expression of SIFamide has been found to be restricted to four neurons of the pars intercerebralis in different holometabolous species. By means of immunohistological stainings, we here show that in Manduca sexta, those four cells are complemented by additional immunoreactive cells located in the vicinity of the mushroom body calyx. Immunopositive processes form arborizations throughout the brain, innervating major neuropils like the antennal lobes, the central complex, and the optic neuropils.