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Encyclopedia > Purkinje cell
Drawing of pigeon Purkinje cells (A) by Santiago Ramon y Cajal
Drawing of pigeon Purkinje cells (A) by Santiago Ramon y Cajal

Purkinje cells are a class of GABAergic neuron located in the cerebellar cortex. They are named after their discoverer, Czech anatomist Jan Evangelista PurkynÄ›. These cells are some of the largest neurons in the brain, with an intricately elaborate dendritic arbor, characterized by a large number of dendritic spines. Purkinje cells are found within the Purkinje layer in the cerebellum. Purkinje cells are aligned like dominos stacked one in front of the other. Their large dendritic arbors form nearly two dimensional layers through which parallel fibers from the deeper-layer granule cells pass. These parallel fibers make relatively weaker excitatory (glutamatergic) synapses to spines in the Purkinje cell dendrite, whereas climbing fibers originating from the inferior olivary nucleus in the medulla provide very powerful excitatory input to the proximal dendrites and cell soma. Parallel fibers pass orthogonally through the Purkinje neuron's dendritic arbor, with up to 200,000 parallel fibers forming a synapse with a single Purkinje cell. Alternatively, each Purkinje cell only receives a synapse from a single climbing fiber. Both basket and stellate cells (found in the cerebellar molecular layer) provide inhibitory (GABAergic) input to the Purkinje cell, with basket cells synapsing on the Purkinje cell body and stellate cells onto the dendrites. Purkinje cells send inhibitory projections to the deep cerebellar nuclei, and constitute the sole output of all motor coordination in the cerebellar cortex. ImageMetadata File history File links Download high resolution version (611x715, 182 KB) Drawing of Purkinje cells (A) and granule cells (B) from pigeon cerebellum by Santiago Ramón y Cajal, 1899. ... ImageMetadata File history File links Download high resolution version (611x715, 182 KB) Drawing of Purkinje cells (A) and granule cells (B) from pigeon cerebellum by Santiago Ramón y Cajal, 1899. ... Santiago Ramon y Cajal Santiago Ramón y Cajal (May 1, 1852 - October 17/18, 1934) was a famous Spanish histologist and father of neuroscience. ... Chemical structure of GABA Gamma-aminobutyric acid (GABA) is a neurotransmitter in widely divergent species. ... Figure 1a: A human brain, with the cerebellum in purple. ... Greek anatome, from ana-temnein, to cut up), is the branch of biology that deals with the structure and organization of living things; thus there is animal anatomy (zootomy) and plant anatomy (phytonomy). ... Jan Evangelista PurkynÄ› (also written Johannes Evangelists Purkinje,  listen?) (1787 - 1869) was a Czech anatomist, patriot, and physiologist. ... Cells in culture, stained for keratin (red) and DNA (green) The cell is the structural and functional unit of all living organisms, and are sometimes called the building blocks of life. ... Neurons (also spelled neurones or called nerve cells) are the primary cells of the nervous system. ... Please help to figure out license type for the image Comparative brain sizes. For other articles about other subjects named brain see brain (disambiguation). ... (The term dendrite may also refer to the metallurgical dendrite. ... Close up of the dendrite of a striatal medium spiny neuron. ... Figure 1a: A human brain, with the cerebellum in purple. ... Figure 1a: A human brain, with the cerebellum in purple. ... Domino redirects here—for other meanings of the word, see Domino (disambiguation). ... Dimension (from Latin measured out) is, in essence, the number of degrees of freedom available for movement in a space. ... Parallel fibers arise from granule cells in the cerebellar cortex. ... In neuroscience, granule cells are tiny cells found within the granular layer of the cerebellum. ... In neuroscience, an excitatory postsynaptic potential (EPSP) is a temporary decrease in postsynaptic membrane potential caused by the flow of positively-charged ions into the postsynaptic cell. ... Glutamic acid or glutamate (the anionic form of glutamic acid) is one of the 20 most common natural amino acids. ... Climbing fibers are the name given to a series of neuronal projections from the inferior olivary nucleus located in the medulla. ... In anatomy, the olivary bodies or simply olives (Latin oliva) are a pair of prominent oval structures in the medulla oblongata, the lower portion of the brainstem. ... Medulla can refer to: The medulla oblongata, a part of the brainstem Medulla, Florida, a U.S. city The 2004 music album Medúlla by Icelandic singer Björk. ... In mathematics, orthogonal is synonymous with perpendicular when used as a simple adjective that is not part of any longer phrase with a standard definition. ... Illustration of the major elements in a prototypical synapse. ... Figure 1a: A human brain, with the cerebellum in purple. ... Inhibitory Postsynaptic Potential is commonly abbreviated to Impulses are transmitted from neuron to neuron by the release of a chemical transmitter across synaptic clefts from the synaptic vesicles along the axon to the postsynaptic receptors of another neuron. ... ...


Purkinje cells show two distinct forms of electrophysiological activity. Simple spikes occur when mossy fibers activate granule cell parallel fibers via amplitude-invariant, "all or nothing" action potential propagation. Simple spikes occur spontaneously at rates of 50 - 150/s. Complex spikes are large, amplitude variant (gradiant), plateau-potentials caused by climbing fiber activation, and involve the generation of calcium-mediated action potentials in the dendrites. During complex spike activity simple spikes are suppressed or washed-out by the powerful complex spike input. Purkinje cells show spontaneous electrophysiological activity in the form of bursts, which may be important for cerebellar function. Climbing fiber activation of the Purkinje cell can shift its activity from a quiet state to a spontaneously bursting state, and vice-versa, serving as a type of switch. Mossy fibers or mossy cells provide stimulation to inhibitory GABA interneurons in the hippocampus. ... Amplitude is a nonnegative scalar measure of a waves magnitude of oscillation, that is, magnitude of the maximum disturbance in the medium during one wave cycle. ...


  Results from FactBites:
 
AND Corporation (495 words)
This is the principal cell of the cerebellum.
The Purkinje cell body is located in the Purkinje layer between the molecular layer and granule layers.
It is estimated that ~2 x 1E9 granule cells exist within the cerebellum, located in the deepest cortical layer of the cerebellum called the granular layer.
Purkinje cell (419 words)
These cells are some of the largest neurons in the brain, with an intricately elaborate dendritic arbor, characterized by a large number of dendritic spines.
Purkinje cells send inhibitory projections to the deep cerebellar nuclei, and constitute the sole output of all motor coordination in the cerebellar cortex.
Purkinje cells show spontaneous electrophysiological activity in the form of bursts, which may be important for cerebellar function.
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