neuron projection

Definition

Target type: cellularcomponent

A prolongation or process extending from a nerve cell, e.g. an axon or dendrite. [GOC:jl, http://www.cogsci.princeton.edu/~wn/]

Neuron projections, also known as axons and dendrites, are specialized cellular extensions that transmit signals between neurons and other cells. These projections are complex structures comprised of various components, each contributing to their function.

1. Axon: The axon is a long, slender projection that carries nerve impulses away from the neuron cell body. It is typically covered by a myelin sheath, a fatty substance that insulates the axon and speeds up signal transmission.

2. Dendrite: Dendrites are branched projections that receive signals from other neurons. They have a large surface area that allows them to make numerous connections with other neurons. Dendrites contain specialized receptors that bind to neurotransmitters released from presynaptic terminals, triggering electrical signals.

3. Synapse: The synapse is the junction between the presynaptic terminal of one neuron and the postsynaptic membrane of another neuron or target cell. At the synapse, electrical signals are converted into chemical signals, and neurotransmitters are released from the presynaptic neuron to bind to receptors on the postsynaptic neuron.

4. Presynaptic terminal: The presynaptic terminal is the end of the axon where neurotransmitters are stored and released. It contains numerous vesicles filled with neurotransmitters.

5. Postsynaptic membrane: The postsynaptic membrane is the membrane of the receiving neuron or target cell that contains receptors for neurotransmitters.

6. Myelin sheath: The myelin sheath is a fatty substance that insulates the axon and speeds up signal transmission. It is formed by specialized glial cells, such as Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system.

7. Nodes of Ranvier: Nodes of Ranvier are gaps in the myelin sheath that expose the axon membrane. These gaps allow for rapid signal transmission by allowing the electrical signal to jump from one node to the next.

8. Axon hillock: The axon hillock is the region where the axon emerges from the cell body. It is an important area for integrating signals from dendrites and generating action potentials.

9. Cytoskeleton: The cytoskeleton is a network of protein filaments that provides structural support and helps to transport materials within the neuron projection.

10. Microtubules: Microtubules are hollow tubes that play a crucial role in intracellular transport. They serve as tracks for motor proteins that carry vesicles and other cellular components along the axon and dendrites.

11. Neurofilaments: Neurofilaments are intermediate filaments that provide mechanical support and strength to the neuron projection.

12. Actin filaments: Actin filaments are thin protein fibers that play a role in the formation and maintenance of the neuron projection's shape.

13. Growth cone: The growth cone is a specialized structure at the tip of a developing neuron projection that helps to guide the growth of the projection towards its target.

14. Axonal transport: Axonal transport is the process of moving materials along the axon, including proteins, lipids, and organelles. This process is essential for maintaining the structural and functional integrity of the neuron projection.

15. Synaptic vesicles: Synaptic vesicles are small, membrane-bound sacs that store neurotransmitters in the presynaptic terminal.

16. Neurotransmitter receptors: Neurotransmitter receptors are proteins embedded in the postsynaptic membrane that bind to neurotransmitters and trigger intracellular signaling pathways.

17. Glial cells: Glial cells are non-neuronal cells that support and protect neurons. They play important roles in myelination, nutrient supply, and waste removal.

18. Extracellular matrix: The extracellular matrix is a network of molecules that surrounds the neuron projection and provides structural support, regulates cell adhesion, and influences neuronal function.

19. Blood vessels: Blood vessels supply the neuron projection with oxygen and nutrients, and remove waste products.

20. Ion channels: Ion channels are proteins that span the cell membrane and allow for the movement of ions, such as sodium, potassium, and calcium, across the membrane. These channels are essential for generating and propagating electrical signals in neurons.
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Proteins (118)

Compounds (1,659)