parallel fiber

Definition

Target type: cellularcomponent

A parallel fiber results from the bifurcation of a cerebellar granule cell axon in the molecular layer into two diametrically opposed branches, that are oriented parallel to the long axis of the folium. [ISBN:0195159551, NIF_Subcellular:nlx_330]

Parallel fibers are slender axons of granule cells, a type of neuron found in the cerebellar cortex. They extend horizontally along the surface of the cerebellar cortex and form synapses with the dendrites of Purkinje cells, the primary output neurons of the cerebellum.

Parallel fibers are characterized by their high density and parallel arrangement, creating a dense network of axons that run perpendicular to the Purkinje cell dendrites. This arrangement allows for a large number of synapses between parallel fibers and Purkinje cells, facilitating efficient communication between these neuronal populations.

Parallel fibers contain a variety of specialized structures and molecules that contribute to their function. They are enriched in glutamate, the primary excitatory neurotransmitter in the brain, which is released at the synapses between parallel fibers and Purkinje cells. These synapses, known as parallel fiber-Purkinje cell synapses, are characterized by their high synaptic strength and ability to induce long-term potentiation (LTP), a form of synaptic plasticity that is crucial for learning and memory.

The parallel fiber network also plays a key role in coordinating the activity of Purkinje cells. As parallel fibers fire in a synchronous manner, they can activate multiple Purkinje cells simultaneously, contributing to the cerebellum's role in motor control, learning, and coordination.

In addition to synapses with Purkinje cells, parallel fibers also form synapses with other neuronal populations in the cerebellar cortex, including interneurons and Golgi cells. These synapses are thought to modulate the activity of parallel fibers and contribute to the fine-tuning of cerebellar circuits.

In summary, parallel fibers are a critical component of the cerebellar cortex, forming a dense network of axons that connect granule cells to Purkinje cells. They are responsible for transmitting excitatory signals from granule cells to Purkinje cells, contributing to the cerebellum's roles in motor control, learning, and coordination.'
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Proteins (1)

Compounds (1)