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]]