cerebellar mossy fiber

Definition

Target type: cellularcomponent

An axon arising from cerebellar projecting cells in the cochlea, vestibular nuclei, spinal cord, reticular formation, cerebellar nuclei and basilar pontine nuclei. Mossy fibers enter through all three cerebellar peduncles and send collaterals to the deep cerebellar nuclei, then branch in the white matter and terminate in the granule cell layer. Through this branching, a given mossy fiber can innervate several folia. Mossy fibers synapse on granule cells. The synaptic contacts are made at enlargements along the length of the mossy fiber called mossy fiber rosettes. The enlargements of the rosettes give the axons a mossy-looking appearance in Golgi stained preparations. [NIF_Subcellular:nlx_subcell_20090209]

Cerebellar mossy fibers are a type of presynaptic axon that originates from various sources in the brainstem and spinal cord, including the pontine nuclei, the inferior olive, the reticular formation, and the dorsal spinocerebellar tract. These fibers project to the cerebellar cortex, specifically to the granular layer, where they form synapses with granule cells. The cellular component of a mossy fiber includes:

- **Axon:** The primary component of the mossy fiber, which is a long, slender projection that travels from the cell body to the cerebellum.
- **Axon terminal:** The end of the mossy fiber that forms synapses with granule cells. These terminals are characterized by their large size and complex morphology, with multiple branches and boutons.
- **Synaptic vesicles:** Small, membrane-bound organelles within the axon terminal that contain neurotransmitters, such as glutamate, which are released into the synaptic cleft during neurotransmission.
- **Mitochondria:** Energy-producing organelles within the axon terminal that provide ATP for synaptic transmission.
- **Cytoskeleton:** A network of protein filaments that provides structural support and facilitates transport within the axon.
- **Myelin sheath:** A fatty covering that insulates the axon and speeds up the conduction of nerve impulses. However, mossy fibers are not typically myelinated, particularly in their terminal regions.
- **Presynaptic proteins:** Various proteins that are involved in regulating synaptic transmission, including those involved in neurotransmitter release, receptor activation, and synaptic plasticity.

These components work together to ensure efficient and reliable transmission of signals from the brainstem and spinal cord to the cerebellar cortex, contributing to the regulation of movement, balance, and coordination.'
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Proteins (4)

Compounds (5)