Скачать или смотреть 3D Histogenesis of Neural Tube - Neuroembryology Part 2

In this visual medical lecture, Dr. Aizaz from MedicoVisual talks about Histogenesis of Neural Tube.

From Simple to Pseudostratified: The Epithelial Transformation
We begin with the neural tube, initially composed of simple columnar epithelium, a single layer of tall, columnar cells. As these cells proliferate, they jostle for space within the limited confines of the tube. This jostling leads to a fascinating transformation, converting the simple epithelium into pseudostratified columnar epithelium.

Radial Glial Cells: The Scaffolding of the Nervous System

Within the pseudostratified epithelium, a new type of cell emerges: the radial glial cell. These remarkable cells extend from the luminal surface of the neural tube to the pial surface, acting as a scaffolding system for the developing nervous system.

Migration of Neuroblasts: A Journey Along Radial Glial Processes

As neuroblasts, the precursors to neurons, are formed, they embark on a remarkable journey. With the help of their own processes, they climb along the radial glial cell processes, much like monkeys climbing trees, to reach their designated positions in the developing nervous system.

The Formation of Layers: Mantle, Marginal, and Ventricular Zones

As neuroblasts migrate and differentiate, they form distinct layers within the neural tube. The mantle layer, composed primarily of neuronal cell bodies, becomes the main layer of the nervous system. The marginal layer, located externally, is rich in nerve fibers (axons). The ventricular zone, closest to the lumen of the neural tube, serves as the birthplace of new neurons.

Glial Cells: Supporting the Nervous System

Radial glial cells also give rise to glial cells, the supporting cells of the nervous system. These include astrocytes, which play a crucial role in maintaining ionic balance, providing nutrition, and forming the blood-brain barrier, and oligodendrocytes, which myelinate nerve fibers in the CNS.

Ependymal Cells: Lining the Central Canal and Ventricles

The remaining radial glial cells in the ventricular zone transform into ependymal cells, lining the central canal of the spinal cord and the ventricles of the brain. These cells contribute to the production of cerebrospinal fluid, providing cushioning and support to the CNS.

Microglia: The Immune Cells of the CNS

Finally, we encounter microglia, the immune cells of the CNS. These cells originate from the bone marrow and reach the CNS as blood vessels develop. Microglia act as specialized macrophages, clearing debris and fighting off invaders.

Stem Cells: The Potential of Radial Glial Cells

Radial glial cells exhibit remarkable potential, acting as stem cells that can self-renew and differentiate into various cell types, including neurons, neuroglia, and ependymal cells. This multipotency makes them a key player in the development and regeneration of the nervous system.