neuropores

Neuropores are openings at the rostral (anterior) and caudal (posterior) ends of the neural tube in the developing embryo. They allow communication between the neural tube lumen and the surrounding amniotic cavity during neural tube formation. The two neuropores are the anterior (cranial) neuropore and the posterior (caudal) neuropore. Closure of the neural tube proceeds from the middle toward both ends; in humans, the cranial neuropore typically closes by about day 25 of gestation, and the caudal neuropore by about days 27–29. After closure, the neuropores are no longer present in the mature nervous system.

Failure of neuropore closure can lead to neural tube defects. Cranial neuropore failure can result in anencephaly or exencephaly, while caudal neuropore failure can lead to spina bifida, including myelomeningocele or more severe forms such as rachischisis. These defects may be detected prenatally by elevated maternal serum or amniotic fluid alpha-fetoprotein and by ultrasound. Neuropore development is a key aspect of early embryogenesis and crucial for the proper formation of the brain and spinal cord.