The
neural fold is a structure that arises during
neurulation in the embryonic development of both
birds and
mammals among other organisms. This structure is associated with primary neurulation, meaning that it forms by the coming together of tissue layers, rather than a clustering, and subsequent hollowing out, of individual cells (known as secondary neurulation). In humans, the neural folds are responsible for the formation of the
anterior end of the
neural tube. The neural folds are derived from the
neural plate, a preliminary structure consisting of elongated
ectoderm cells. The folds give rise to
neural crest cells, as well as bringing about the formation of the
neural tube.