optic nerve development

Definition

Target type: biologicalprocess

The process whose specific outcome is the progression of the optic nerve over time, from its formation to the mature structure. The sensory optic nerve originates from the bipolar cells of the retina and conducts visual information to the brainstem. The optic nerve exits the back of the eye in the orbit, enters the optic canal, and enters the central nervous system at the optic chiasm (crossing) where the nerve fibers become the optic tract just prior to entering the hindbrain. [GO_REF:0000021, GOC:cls, GOC:dgh, GOC:dph, GOC:jid, ISBN:0838580343]

Optic nerve development is a complex and intricate process that begins early in embryonic development and continues throughout postnatal life. It involves the coordinated action of multiple cell types, signaling pathways, and genetic programs. The optic nerve, a bundle of nerve fibers that connects the eye to the brain, plays a crucial role in vision. Here is a detailed description of its development:

**1. Optic Vesicle Formation and Outgrowth:**
* The optic nerve originates from the optic vesicle, an outgrowth of the developing brain's diencephalon.
* The optic vesicle evaginates from the neural tube and extends towards the surface ectoderm, where it induces the formation of the lens placode.

**2. Lens Induction and Retinal Differentiation:**
* The optic vesicle interacts with the lens placode, inducing its invagination and differentiation into the lens.
* The optic vesicle itself transforms into the optic cup, which will give rise to the retina, the light-sensitive tissue of the eye.

**3. Optic Stalk Formation and Axon Extension:**
* As the optic cup develops, the connection between the cup and the diencephalon narrows, forming the optic stalk.
* Retinal ganglion cells (RGCs), the neurons that transmit visual information from the eye to the brain, begin to differentiate within the retina.
* RGC axons, the extensions of these neurons, grow out from the retina and into the optic stalk.

**4. Optic Nerve Formation and Myelination:**
* As RGC axons extend into the optic stalk, they become bundled together to form the optic nerve.
* The optic nerve grows in length as the eye continues to develop.
* Glial cells, including oligodendrocytes and Schwann cells, migrate into the optic nerve and myelinate the axons, providing insulation and supporting their function.

**5. Optic Nerve Target Selection and Refinement:**
* RGC axons navigate through the optic nerve and reach their targets in the brain, primarily the lateral geniculate nucleus (LGN) and superior colliculus.
* During this process, axons undergo target selection, ensuring that they reach the correct targets in the brain.
* This selection is guided by chemoattractants and chemorepellents, molecular cues that guide axonal growth and target recognition.

**6. Postnatal Development and Refinement:**
* After birth, the optic nerve continues to develop and refine its connections.
* Synaptic plasticity, the ability of synapses to change in strength, allows for the fine-tuning of visual circuits.
* Environmental factors, including visual experience, play a role in shaping the development and function of the optic nerve.

**7. Optic Nerve Regeneration:**
* The optic nerve has limited regenerative capacity, unlike some other parts of the nervous system.
* In the event of injury, RGC axons often fail to regenerate and re-establish functional connections.
* However, research is ongoing to identify strategies that could promote optic nerve regeneration and restore vision after injury.'
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Proteins (7)

Compounds (50)