Granule cell
2412513
210442990
2008-05-05T23:17:32Z
Ahimsa52
503538
Deleted repetitive internal link + deleted abberant link to "excitatory"
:''Granular cell also refers to [[Juxtaglomerular cell]] in the kidney''
[[Image:PurkinjeCell.jpg|thumb|right|200px|Drawing of [[Purkinje cell]]s (A) and granule cells (B) from pigeon cerebellum by [[Santiago Ramón y Cajal]], 1899. Instituto Santiago Ramón y Cajal, Madrid, Spain.]]
In [[neuroscience]], '''granule cells''' refer to tiny neurons (a type of [[Cell_(biology)|cell]]) that are around 10 micrometres in diameter. Granule cells are found within the [[Cerebellum#Granular_Layer|granular layer]] of the [[cerebellum]], layer 4 of [[cerebral cortex]], the [[dentate gyrus]] of the [[hippocampus]], and in the [[olfactory bulb]].
While anatomically similar, granule cells in different brain regions are functionally diverse. For instance, olfactory bulb granule cells are [[GABA]]ergic and axonless, while granule cells in the dentate gyrus have [[glutamate]]rgic projection [[axon]]s. Interestingly, these two populations of granule cells are also the only major neuronal populations that undergo [[Neurogenesis|adult neurogenesis]], while cerebellar and cortical granule cells do not.
Cerebellar granule cells account for nearly half of the [[neuron]]s in the [[central nervous system]]. Granule cells receive excitatory input from [[mossy fiber]]s originating from [[pons|pontine]] [[nucleus (neuroanatomy)|nuclei]]. Cerebellar granule cells send [[parallel fiber]]s up through the [[Cerebellum#Purkinje_Layer|Purkinje layer]] into the [[Cerebellum#molecular_Layer|molecular layer]] where they branch out and spread through [[Purkinje cell]] [[dendrite|dendritic]] arbors. These parallel fibers form thousands of excitatory [[synapse]]s onto the intermediate and distal dendrites of Purkinje cells using glutamate as a neurotransmitter.
Layer 4 granule cells of the cerebral cortex receive driving inputs from [[thalamus]] and convey driving inputs largely to supragranular layers 2-3, but also to infragranular layers of the cerebral cortex.
==External links==
* {{BrainMaps|Granule%20cells|Granule cells}}
{{Nervous tissue}}
{{Cerebellum}}
[[Category:CNS neurons]]
[[Category:Cerebellum]]
{{neuroanatomy-stub}}
[[ca:Cèl·lula granulosa]]
[[de:Körnerzelle]]
[[ru:Гранулярная клетка]]