neuronal stem cell population maintenance

Definition

Target type: biologicalprocess

Any process in by an organism or tissue maintains a population of neuronal stem cells. [CL:0000047, GOC:dos, GOC:yaf, PMID:11399758]

Neuronal stem cell (NSC) population maintenance is a complex process that involves a delicate balance of self-renewal, differentiation, and survival, ensuring a constant supply of new neurons throughout life. This intricate process is governed by a network of intrinsic and extrinsic factors, each playing a crucial role in shaping the NSC fate.

**Intrinsic Factors:**

* **Transcription Factors:** Specific transcription factors, such as Sox2, Oct4, and Nanog, are essential for maintaining NSC identity and self-renewal. They directly regulate gene expression, ensuring that NSCs retain their pluripotency and proliferative capacity.
* **Epigenetic Regulation:** Modifications of DNA and histones, collectively known as epigenetic modifications, play a critical role in regulating gene expression. These modifications can be influenced by environmental cues and can alter the accessibility of genes involved in NSC maintenance.
* **Cell Cycle Control:** NSCs exhibit a distinct cell cycle profile, with tight control over entry into and progression through the cell cycle. Specific cyclin-dependent kinases and their inhibitors regulate this process, ensuring balanced proliferation and differentiation.

**Extrinsic Factors:**

* **Niche Microenvironment:** NSCs reside within specialized microenvironments, termed niches, that provide essential cues for their survival and self-renewal. These niches are comprised of various cell types, including astrocytes, microglia, and vascular cells, which contribute to the NSC niche by secreting growth factors, providing structural support, and maintaining an appropriate oxygen and nutrient supply.
* **Signaling Pathways:** Various signaling pathways, such as the Wnt, Shh, and Notch pathways, are critical for NSC maintenance. These pathways activate specific transcription factors and other downstream targets, influencing cell fate decisions, proliferation, and survival.
* **Growth Factors:** A diverse array of growth factors, including fibroblast growth factors (FGFs), epidermal growth factors (EGFs), and neurotrophins, promote NSC self-renewal and survival. They activate signaling pathways and regulate gene expression, ensuring NSC maintenance.

**Mechanisms of Maintenance:**

* **Symmetrical Division:** NSCs can undergo symmetrical division, producing two identical daughter cells that retain their NSC identity, thereby expanding the pool of NSCs.
* **Asymmetrical Division:** Alternatively, NSCs can undergo asymmetrical division, giving rise to one NSC daughter cell and one progenitor cell, which is committed to differentiation. This process allows for the generation of new neurons while maintaining the NSC pool.
* **Quiescence:** A subset of NSCs exists in a quiescent state, characterized by low metabolic activity and a reduced rate of proliferation. This quiescent state serves as a reserve pool of NSCs, ensuring that the population can be replenished upon demand.

**Significance:**

Maintaining a healthy NSC population is critical for brain development, plasticity, and repair. NSCs are responsible for generating new neurons throughout life, contributing to learning, memory, and cognitive function. Furthermore, NSCs can be activated in response to injury or disease, playing a role in tissue repair and regeneration.

Understanding the intricacies of NSC maintenance is paramount for developing therapies for neurodegenerative diseases, stroke, and other neurological conditions. By manipulating the factors that regulate NSC self-renewal, differentiation, and survival, it may be possible to promote neurogenesis and improve brain function.'
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Proteins (4)

Compounds (5)