rostral interstitial nucleus of medial longitudinal fasciculus rostral interstitial nucleus of medial longitudinal fasciculus the rostral interstitial nucleus of medial longitudinal fasciculus (rimlf) is a portion of the medial longitudinal fasciculus which controls vertical gaze. rostral interstitial nucleus of medial longitudinal fasciculusaxial section through mid-brain. (nucleus is not labeled, but mlf is "b", in red.)detailsidentifierslatinnucleus interstitialisneuronames516neurolex idbirnlex_1481anatomical terms of neuroanatomy they project to the vestibular nuclei.