Anomalies of Dorsal Induction: Neural Tube Defects

Abstract

Dorsal induction refers to the development of the neural tube as a result of induction by the notochord. The notochord develops during the third week of conceptual age along the cephalocaudal axis of the trilaminar embryo. It induces the neural plate (neurectoderm) to form the neural groove. The neural groove closes to form the neural tube between the 22nd and 26th day of conceptual age. The rostral and caudal neuropores close by the 24th and 26th days of conceptual age, respectively. The process of dorsal induction is also referred to as primary neurulation. The neural tube gives rise to the brain and spinal cord. Total or partial failure of closure of the neural groove results in neural tube defects (defects of dorsal induction).