Floor plate

Definition

The floor plate is a structure in the developing nervous system that serves as a signaling center, guiding the growth and differentiation of neurons during embryonic development. This area is located along the ventral midline of the neural tube and plays a crucial role in establishing the organization of the spinal cord and other regions of the central nervous system. By releasing specific molecular signals, the floor plate influences the fate of surrounding progenitor cells and helps establish neuronal pathways.

5 Must Know Facts For Your Next Test

1. The floor plate originates from the notochord and is critical for proper dorsal-ventral patterning in the developing nervous system.
2. It provides essential guidance cues for axon growth, helping to direct neuronal projections towards their target areas.
3. The floor plate is rich in signaling molecules like sonic hedgehog (Shh), which influences cell fate decisions in nearby progenitor cells.
4. Dysfunction or abnormalities in the floor plate can lead to various developmental disorders and neuroanatomical defects.
5. During development, the floor plate also contributes to the formation of specific neuronal subtypes within the spinal cord and brain.

Review Questions

• How does the floor plate influence neuronal development during embryogenesis?
  • The floor plate influences neuronal development by acting as a signaling center that releases key molecular signals, such as sonic hedgehog (Shh). These signals help determine the fate of surrounding progenitor cells, guiding them to differentiate into specific types of neurons. Additionally, by directing axon growth and establishing connections between neurons, the floor plate ensures proper organization and functionality of the nervous system.
• What are some potential consequences of abnormalities in floor plate development on the central nervous system?
  • Abnormalities in floor plate development can result in significant disruptions in central nervous system organization and function. For instance, improper signaling from the floor plate may lead to misrouting of axons or failure to produce specific neuronal subtypes, contributing to developmental disorders such as spina bifida or other neural tube defects. These conditions can have lifelong impacts on motor function, sensory processing, and overall neurological health.
• Evaluate the role of sonic hedgehog (Shh) secreted by the floor plate in establishing neuronal identity and connections within the developing spinal cord.
  • Sonic hedgehog (Shh) secreted by the floor plate plays a pivotal role in establishing neuronal identity by providing critical signals that dictate cell fate decisions among progenitor cells in the spinal cord. The gradient of Shh influences whether these progenitors become motor neurons or interneurons, thus shaping the functional landscape of the spinal cord. Furthermore, Shh signaling aids in guiding axonal growth, ensuring that developing neurons form appropriate connections necessary for a functioning neural network. Disruptions in this signaling pathway can lead to aberrant neuronal identities and dysfunctional circuitry within the spinal cord.

Related terms

neural tube:

The embryonic structure that develops into the central nervous system, consisting of the brain and spinal cord.

sonic hedgehog (Shh): A signaling molecule secreted by the floor plate that is essential for establishing ventral-dorsal patterning in the developing nervous system.

ventricular zone: A layer of neural progenitor cells located adjacent to the neural tube's lumen, from which neurons and glial cells are generated during development.