midbrain ventro-caudal cluster Early-forming neural cluster of the ventral midbrain. At 16 h, axons of the vcc grow caudally to pioneer the medial longitudinal fasciculus (MLF), which is part of the larger ventral longitudinal tract (VLT). Later, neurons from this cluster project axons rostrally into the tract of the post-optic commissure (TPOC). Ross et al., 1992. TAO:0007003 teleost_anatomy vcc ventrocaudal cluster