Parallel fiber
Encyclopedia
Parallel fibers arise from granule cell
s in the cerebellar cortex
. They form excitatory synapse
s onto the dendrite
s of Purkinje cell
s (the output neuron
s of the cerebellum
).
Granule cells are very small and very numerous. They are thought to make up as many as half of the neurons in the brain. Granule cells have axon
s which rise up and then branch out into parallel fibers. These fibers intersect the Purkinje cell dendrites.
Granule cell
In neuroscience, granule cells refer to tiny neurons that are around 10 micrometres in diameter. Granule cells are found within the granular layer of the cerebellum , the dentate gyrus of the...
s in the cerebellar cortex
Cerebellum
The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...
. They form excitatory synapse
Synapse
In the nervous system, a synapse is a structure that permits a neuron to pass an electrical or chemical signal to another cell...
s onto the dendrite
Dendrite
Dendrites are the branched projections of a neuron that act to conduct the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project...
s of Purkinje cell
Purkinje cell
For the cells of the electrical conduction system of the heart, see Purkinje fibersPurkinje cells, or Purkinje neurons , are a class of GABAergic neurons located in the cerebellar cortex...
s (the output neuron
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...
s of the cerebellum
Cerebellum
The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...
).
Granule cells are very small and very numerous. They are thought to make up as many as half of the neurons in the brain. Granule cells have axon
Axon
An axon is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body or soma....
s which rise up and then branch out into parallel fibers. These fibers intersect the Purkinje cell dendrites.