The term insular stem refers to a superficial feature of the junction of the insula with the orbital gyri of the frontal lobe and the parahippocampal gyrus of the temporal lobe. It as identified by dissection in the human. It is composed of the limen insula laterally and the surface of the transverse insular gyrus medially ( Ture-1999 ). It is not found in the macaque ( Mufson-1997 ) or the rodent ( NeuroNames ).