telencephalon cell migration

Definition

Target type: biologicalprocess

The orderly movement of a cell from one site to another at least one of which is located in the telencephalon. [GO_REF:0000021, GOC:cls, GOC:curators, GOC:dgh, GOC:dph, GOC:jid]

Telencephalon cell migration is a complex and highly regulated process that involves the movement of newly generated neurons from their birthplace in the ventricular zone to their final destination in the developing cerebral cortex. This intricate journey is essential for the formation of the highly organized and functional structure of the brain.

The process begins with the proliferation of neural progenitor cells in the ventricular zone, a layer lining the ventricles of the brain. These progenitor cells undergo multiple rounds of cell division, giving rise to a vast population of neurons. Newly generated neurons, known as neuroblasts, then embark on a remarkable journey, migrating radially outward from the ventricular zone to their final position in the developing cortex.

**Radial Migration:**

Radial migration is the primary mode of neuronal migration in the telencephalon. It involves the movement of neuroblasts along radial glial fibers, which act as scaffolding pathways extending from the ventricular zone to the pial surface. Radial glial cells, themselves a type of progenitor cell, play a crucial role in guiding the migration of neuroblasts.

Neuroblasts attach to the radial glial fibers through specialized adhesion molecules, such as integrins and cadherins. They then move along these fibers, using a combination of mechanisms, including:

* **Somatodendritic translocation:** The neuroblast extends a leading process, called the leading edge, along the radial glial fiber, while the cell body (soma) and dendrites follow behind.
* **Nuclear translocation:** The nucleus of the neuroblast translocates along the radial glial fiber, followed by the rest of the cell.
* **Crawling:** In some cases, neuroblasts can crawl along the radial glial fiber, using filopodia and lamellipodia to propel themselves forward.

**Tangential Migration:**

While radial migration is the dominant form of neuronal migration in the telencephalon, some neurons also undergo tangential migration, moving horizontally across the developing cortex. This type of migration is crucial for establishing specific neuronal circuits and connections.

Tangential migration can be mediated by different mechanisms, including:

* **Cell-autonomous migration:** Some neurons migrate independently, following chemical cues and gradients.
* **Interneuron migration:** Interneurons, a type of neuron that originates in the subventricular zone and migrates tangentially to the cortex, often follow specific pathways and interact with other migrating neurons.

**Regulation of Telencephalon Cell Migration:**

The precise timing, direction, and destination of telencephalon cell migration are tightly regulated by a complex interplay of factors, including:

* **Intrinsic factors:** The neuron's own genetic program and molecular machinery influence its migration.
* **Extrinsic factors:** External cues, such as chemical gradients, cell-cell interactions, and extracellular matrix components, guide and regulate neuronal migration.

**Disruption of Telencephalon Cell Migration:**

Defects in telencephalon cell migration can lead to a variety of neurological disorders, including:

* **Lissencephaly:** A condition characterized by a smooth brain surface due to the failure of neuronal migration.
* **Micropolygyria:** A condition characterized by an abnormally high number of small gyri (folds) in the brain due to aberrant neuronal migration.
* **Schizophrenia:** Some researchers believe that disrupted neuronal migration in the telencephalon may contribute to the development of schizophrenia.

**Conclusion:**

Telencephalon cell migration is a fundamental process in brain development, essential for establishing the intricate organization and functionality of the cerebral cortex. Understanding the mechanisms and regulation of this process is crucial for understanding normal brain development and for developing therapies for neurological disorders associated with migration defects.'
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Proteins (2)

Compounds (13)