Question

What part of the neural tube responds to SHH

Answer 1

In vertebrate embryonic development, the ventral part of the neural tube responds to Sonic Hedgehog (SHH) signaling, which influences the patterning and differentiation of neuronal subtypes.

Step-by-step explanation:

The part of the neural tube that responds to Sonic Hedgehog (SHH) is the ventral portion. During early neural development, SHH signaling is critical for patterning the dorsal-ventral axis of the neural tube. SHH is secreted by the notochord and the floor plate, and it acts to induce the development of ventral neural cell types, particularly in the region that will give rise to motor neurons and interneurons in vertebrates. As the neural tube forms from the fusion of the neural folds, it creates a central cavity known as the neural canal, which runs the length of the tube and functions as a preliminary pathway for the central nervous system.

Organogenesis involves the formation of the central nervous system from the ectoderm of the embryo in a process called neurulation. The notochord and the neural tube play pivotal roles in the patterning and subsequent differentiation of the neural tissue. The proximity of the notochord to the ventral neural tube makes it a prime target for SHH signaling, influencing the specification of neuronal subtypes during embryonic development.

Answer 2

The ventral portion of the neural tube is the part that responds to Sonic Hedgehog (SHH), a key signaling molecule in the patterning of the central nervous system.

Step-by-step explanation:

The part of the neural tube that responds to Sonic Hedgehog (SHH) is the ventral portion. During embryonic development, the neural tube forms from neuroectodermal tissue and is subject to the influence of various signaling molecules.

SHH is a critical morphogen that emanates from the notochord and the floor plate of the neural tube, playing an essential role in patterning the ventral region of the neural tube. This morphogen establishes distinct neuronal subtypes by dictating the dorsal-ventral axis organization of the central nervous system (CNS) via gradient-based mechanisms.

SHH signaling is vital for the proper development of the central nervous system and its impairment can lead to serious congenital defects. It's also important to acknowledge that the neural crest cells, which originate from the dorsal part of the neural tube, give rise to parts of the peripheral nervous system (PNS) and other structures like craniofacial cartilage and bone, and melanocytes, indicating the complexity and significance of neural tube development.