29 Questions
Which glial cell type is derived from the neuroepithelium?
Microglia
Which glial cell type is related to macrophages and derived from the mesoderm?
Microglia
Which glial cell type is responsible for myelination in the CNS?
Oligodendrocytes
Which glial cell type is responsible for myelination in the PNS?
Schwann Cells
Which glial cell type has star-shaped cell bodies and end-feet that contact capillaries or neurons?
Astrocytes
Which glial cell type contributes to the blood-brain barrier and controls extracellular potassium?
Astrocytes
Which part of the nervous system is encased in bone?
CNS
Which cell type is destroyed in multiple sclerosis?
Oligodendrocytes
What is the role of myelin basic protein (MBP) in myelin compaction?
Facilitating myelin compaction
Which disease is used as an experimental model of demyelinating diseases, such as multiple sclerosis?
Experimental allergic encephalomyelitis (EAE)
What is the consequence of a deletion mutation of the MBP gene in mice?
Tremors, convulsions, and early death
Which gene is duplicated in Charcot-Marie-Tooth disease (CMT)?
Peripheral Myelin Protein 22 (PMP22) gene
What is the characteristic of Charcot-Marie-Tooth disease (CMT) caused by the duplicated PMP22 gene?
Weakness and greatly decreased conduction velocity in peripheral nerves
What is the consequence of transplantation of human oligodendrocyte precursor cells in a mouse model of leukodystrophy?
Widespread myelination of the brain
What is the main finding regarding the repopulation of the adult mammalian brain by transplanted OPCs?
Complete repopulation and myelination
How can the shiverer mouse phenotype be rescued?
Injection of human oligodendrocyte precursor cells
What is the g-ratio crucial for in myelin thickness?
Regulating myelin thickness for axons of different diameters
What was observed in the 1950s using electron microscopy, revealing the composition of compact myelin?
Myelin compaction in the developing PNS
What do proteins associated with compact myelin, such as myelin basic protein (MBP) and proteolipid protein (PLP), play key roles in?
Linking and compacting the extracellular face of the plasma membrane
What is responsible for linking and compacting the extracellular face of the plasma membrane, with evidence suggesting its complex trafficking and regulation?
Proteolipid protein (PLP)
What are demyelinating diseases, such as multiple sclerosis, major risk factors for?
Vitamin D deficiency
What is involved in myelin biogenesis in the CNS?
Generation of a spiral wrap of membrane followed by compaction and formation of compact myelin
What is the primary function of astrocytes in relation to neurons?
Storing glycogen and supplying neurons with glucose and lactate
Where do oligodendrocyte precursor cells (OPCs) originate from?
Ventricular zone of the neural tube
What directs the migration of OPCs in the developing neural tube?
Secreted chemotropic guidance cues such as netrins
What is the role of netrin-1 in the developing neural tube?
Influencing cell migration and adhesion through its receptors DCC and UNC5
What distinguishes the myelination process in the CNS from the PNS?
Oligodendrocytes in the CNS myelinate multiple axons simultaneously
What is the function of myelin around axons?
Providing electrical insulation and allowing for faster conduction of electrical signals
Who first described myelin and is known for contributions to social medicine and modern pathology?
Dr. Rudolf Virchow
Study Notes
Neuroglia: Myelinating Glia and Their Development
- Astrocytes store glycogen and supply neurons with glucose and lactate, and they remove excess potassium from the extracellular space
- Myelinating glia include oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS)
- Myelination occurs around axons to provide electrical insulation, and myelin allows for faster conduction of electrical signals
- Myelin was first described in 1854 by Dr. Rudolf Virchow, who is remembered for his contributions to social medicine and modern pathology
- Oligodendrocytes in the CNS myelinate multiple axons simultaneously, while Schwann cells in the PNS wrap around a single axon
- Oligodendrocyte precursor cells (OPCs) in the ventricular zone of the neural tube give rise to oligodendrocytes, while Schwann cells originate from the neural crest
- OPCs migrate and proliferate to populate all myelinated regions of the CNS, and their development involves the establishment of contact with axons and myelin formation
- OPC migration is directed by secreted chemotropic guidance cues such as netrins, which form a ventral to dorsal gradient in the developing neural tube
- Netrins are a family of secreted proteins related to laminins, and they can attract or repel neurons during neural development
- Netrin-1 is made in the floor plate at the ventral midline of the developing neural tube, and it influences cell migration and adhesion through its receptors DCC and UNC5
- OPCs express DCC and UNC5A & B, allowing them to respond to netrin-1 as an attractant or a repellent depending on the cellular context
- Netrins regulate cytoskeletal organization to direct migration and influence cell-substrate and cell-cell adhesion, but much about their signal transduction is still unknown
Test your knowledge of neuroglia and their role in myelination with this quiz. Explore the functions of astrocytes, oligodendrocytes, and Schwann cells, and learn about the development and migration of myelinating glia. Delve into the fascinating world of netrins and their influence on cell migration and adhesion in the developing neural tube.
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