neuroscience Neuroscience is the science, scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a Multidisciplinary approach, multidisciplinary science that combines physiology, an ...

, Golgi cells are inhibitory interneurons found within the granular layer of the

cerebellum The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cere ...

. They were first identified as inhibitory in 1964. It was also the first example of an inhibitory feedback network, where the inhibitory interneuron was identified anatomically. These cells synapse onto the

dendrite Dendrites (from Greek δένδρον ''déndron'', "tree"), also dendrons, are branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the ...

granule cell A granule is a large particle or grain. It can refer to: * Granule (cell biology), any of several submicroscopic structures, some with explicable origins, others noted only as cell type-specific features of unknown function ** Azurophilic granul ...

s and unipolar brush cells. They receive excitatory input from mossy fibres, also synapsing on granule cells, and

parallel fiber Parallel is a geometric term of location which may refer to: Computing * Parallel algorithm * Parallel computing * Parallel metaheuristic * Parallel (software), a UNIX utility for running programs in parallel * Parallel Sysplex, a cluster o ...

s, which are long granule cell axons. Thereby this circuitry allows for feed-forward and feed-back inhibition of granule cells. The main synapse made by these cells is a synapse onto the mossy fibre - granule cell excitatory synapse in a glomerulus. The glomerulus is made up of the mossy fibre terminal, granule cell

s, the Golgi terminal and is enclosed by a glial coat. The Golgi cell acts by altering the mossy fibre - granule cell synapse. The Golgi cells use GABA as their neurotransmitter. The basal level of GABA produces a postsynaptic leak conductance by tonically activating alpha 6-containing GABA-A receptors on the granule cell. These high-affinity receptors are located both synaptically and extrasynaptically on the granule cell. The synaptic receptors mediate phasic contraction, duration of around 20-30ms whereas the extrasynapatic receptors mediate tonic inhibition of around 200ms, and are activated by synapse spill over. Additionally the GABA acts on GABA-B receptors which are located presynaptically on the mossy fibre terminal. These inhibit the mossy fibre evoked EPSCs of the granule cell in a temperature and frequency dependent manner. At high mossy firing frequency (10 Hz) there is no effect of GABA acting on presynaptic GABA-B receptors on evoked EPSCs. However, at low (1 Hz) firing the GABA does have an effect on the EPSCs mediated via these presynaptic GABA-B receptors.

Golgi type I

A Golgi type I

neuron A neuron, neurone, or nerve cell is an membrane potential#Cell excitability, electrically excitable cell (biology), cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous ...

has a long

axon An axon (from Greek ἄξων ''áxōn'', axis), or nerve fiber (or nerve fibre: see spelling differences), is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action ...

that begins in the grey matter of the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all p ...

and may extend from there. It is also known as a projection neuron. They include the neurons forming peripheral nerves and long tracts of brain and spinal cord. Golgi II neurons, in contrast, are defined as having short axons or no axon at all. This distinction was introduced by the pioneering neuroanatomist

Camillo Golgi Camillo Golgi (; 7 July 184321 January 1926) was an Italian biologist and pathologist known for his works on the central nervous system. He studied medicine at the University of Pavia (where he later spent most of his professional career) betwee ...

, on the basis of the appearance under a microscope of neurons stained with the

Golgi stain Golgi's method is a silver staining technique that is used to visualize nervous tissue under light microscopy. The method was discovered by Camillo Golgi, an Italian physician and scientist, who published the first picture made with the technique ...

that he had invented. Santiago Ramón y Cajal postulated that higher developed animals had more Golgi type II in comparison to Golgi type I neurons. These Golgi type II neurons have a star-like appearance, and are found in cerebral and cerebellar cortices and retina.

Golgi type II

A Golgi type II

either has no axon or else a short

that does not send branches out of the gray matter of the central nervous system.

References

External links

NIF Search - Golgi Cell
via the

Neuroscience Information Framework The Neuroscience Information Framework is a repository of global neuroscience web resources, including experimental, clinical, and translational neuroscience databases, knowledge bases, atlases, and genetic/ genomic resources and provides many aut ...

NIF Search - Golgi II Cell
via the Neuroscience Information Framework {{DEFAULTSORT:Golgi Cell Central nervous system neurons Cerebellum Neurons