part of start stage end stage midbrain hindbrain boundary portion of tissue midbrain hindbrain boundary constriction zebrafish_anatomy 2020-03-04T12:35:25Z A portion of tissue that is the deepest point of the fold of the midbrain hindbrain boundary. In zebrafish the midbrain hindbrain boundary constriction (MHBC) is formed soon after neural tube closure. The MHBC is formed by the bending of the basal side of the neuroepithelium. Yvonne ZFA:0007125 MHBC segmentation:14-19 somites adult