limen insulae limen insulae the limen insulae forms the junction point between anterior and posterior stem of the lateral sulcus. it is the lateral most limit of the anterior perforated substance and the starting point of the insular cortex. limen insulaeidentifiersneuronames2072neurolex idbirnlex_1493ta98a14.1.09.155ta25503fma75266anatomical terms of neuroanatomy the limen insulae translates as the threshold to the insula, and is the point at which the insular cortex is continuous with cortex over the amygdala and superior temporal gyrus.