Editing Pyramidal cell

{{Short description|Projection neurons in the cerebral cortex and hippocampus}}
{{Infobox neuron
|name = Pyramidal cell
|image = GolgiStainedPyramidalCell.jpg
|caption = A human [[Neocortex|neocortical]] pyramidal cell stained via [[Golgi's method]]. The [[apical dendrite]] extends vertically above the [[Soma (biology)|soma]] (cell body) and the numerous [[basal dendrite]]s radiate laterally from the base of the cell body.
|location = [[Cerebral cortex#Layer III|Layer III]] and [[Cerebral cortex#Layer V|layer V]] of the [[cerebral cortex]], the [[hippocampus]], and [[amygdala]]
|function = Excitatory projection neuron
|neurotransmitter = [[Glutamate]]
|morphology = Multipolar pyramidal
}}

'''Pyramidal cells''', or '''pyramidal neurons''', are a type of [[multipolar neuron]] found in areas of the [[brain]] including the [[cerebral cortex]], the [[hippocampus]], and the [[amygdala]]. Pyramidal cells are the primary excitation units of the mammalian [[prefrontal cortex]] and the [[corticospinal tract]]. One of the main structural features of the pyramidal neuron is the conic shaped [[soma (biology)|soma]], or cell body, after which the [[neuron]] is named. Other key structural features of the pyramidal cell are a single [[axon]], a large [[apical dendrite]], multiple [[basal dendrite]]s, and the presence of [[dendritic spines]].<ref name = "Megias">{{cite journal | vauthors = Megías M, Emri Z, Freund TF, Gulyás AI | title = Total number and distribution of inhibitory and excitatory synapses on hippocampal CA1 pyramidal cells | journal = Neuroscience | volume = 102 | issue = 3 | pages = 527–540 | year = 2001 | pmid = 11226691 | doi = 10.1016/S0306-4522(00)00496-6 | s2cid = 16458290 }}</ref> 

Pyramidal neurons are also one of two cell types where the [[pathognomonic|characteristic]] [[Medical sign|sign]], [[Negri bodies]], are found in [[post-mortem]] rabies infection.<ref>{{Cite web|url=https://www.sketchymedical.com/sections/viruses-2-3-rhabdovirus|title=2.3 rhabdovirus|last=Sketchy Group, LLC|website=SketchyMedical|archive-url=https://web.archive.org/web/20170413234842/https://www.sketchymedical.com/sections/viruses%2D2%2D3%2Drhabdovirus|archive-date=2017-04-13|url-status=dead|url-access=subscription }}</ref> Pyramidal neurons were first discovered and studied by [[Santiago Ramón y Cajal]].<ref name="Elston">{{cite journal | vauthors = Elston GN | title = Cortex, cognition and the cell: new insights into the pyramidal neuron and prefrontal function | journal = Cerebral Cortex | volume = 13 | issue = 11 | pages = 1124–1138 | date = November 2003 | pmid = 14576205 | doi = 10.1093/cercor/bhg093 | doi-access = free }}</ref><ref name = "Pablo">{{cite journal | vauthors = García-López P, García-Marín V, Freire M | title = Three-dimensional reconstruction and quantitative study of a pyramidal cell of a Cajal histological preparation | journal = The Journal of Neuroscience | volume = 26 | issue = 44 | pages = 11249–11252 | date = November 2006 | pmid = 17079652 | pmc = 6674523 | doi = 10.1523/JNEUROSCI.3543-06.2006 }}</ref> Since then, studies on pyramidal neurons have focused on topics ranging from [[neuroplasticity]] to [[cognition]].
{{toclimit|3}}

== Structure ==
[[File:Piramidal cell.svg|thumb|A reconstruction of a pyramidal cell. Soma and dendrites are labeled in red, axon arbor in blue. (1) Soma, (2) Basal dendrite, (3) Apical dendrite, (4) Axon, (5) Collateral axon.]]

One of the main structural features of the pyramidal neuron is the conic shaped [[soma (biology)|soma]], or cell body, after which the [[neuron]] is named. Other key structural features of the pyramidal cell are a single [[axon]], a large [[apical dendrite]], multiple [[basal dendrite]]s, and the presence of [[dendritic spines]].<ref name = "Megias" />

===Apical dendrite===
The apical dendrite rises from the apex of the pyramidal cell's soma. The apical dendrite is a single, long, thick dendrite that branches several times as distance from the soma increases and extends towards the cortical surface.<ref name = "Megias" />

===Basal dendrite===
Basal dendrites arise from the base of the soma. The basal dendritic tree consists of three to five primary dendrites. As distance increases from the soma, the basal dendrites branch profusely.<ref name = "Megias" />

Pyramidal cells are among the largest neurons in the brain. Both in humans and rodents, pyramidal cell bodies (somas) average around 20&nbsp;μm in length. Pyramidal dendrites typically range in diameter from half a micrometer to several micrometers. The length of a single dendrite is usually several hundred micrometers. Due to branching, the total dendritic length of a pyramidal cell may reach several centimeters. The pyramidal cell's axon is often even longer and extensively branched, reaching many centimeters in total length.
[[File:GFPneuron.png|thumb|Pyramidal neuron visualized by [[green fluorescent protein]] (GFP)]]
[[File:Hippocampal-pyramidal-cell.png|thumb|A [[hippocampal]] pyramidal cell]]

===Dendritic spines===

[[Dendritic spines]] receive most of the excitatory impulses ([[Excitatory postsynaptic potential|EPSP]]s) that enter a pyramidal cell. Dendritic spines were first noted by Ramón y Cajal in 1888 by using [[Golgi's method]]. Ramón y Cajal was also the first person to propose the physiological role of increasing the receptive surface area of the neuron. The greater the pyramidal cell's surface area, the greater the neuron's ability to process and integrate large amounts of information. Dendritic spines are absent on the soma, while the number increases away from it.<ref name ="Pablo" /> The typical apical dendrite in a rat has at least 3,000 dendritic spines. The average human apical dendrite is approximately twice the length of a rat's, so the number of dendritic spines present on a human apical dendrite could be as high as 6,000.<ref name="LaBerge">{{cite journal | vauthors = Laberge D, Kasevich R | title = The apical dendrite theory of consciousness | journal = Neural Networks | volume = 20 | issue = 9 | pages = 1004–1020 | date = November 2007 | pmid = 17920812 | doi = 10.1016/j.neunet.2007.09.006 }}</ref>

==Growth and development==

===Differentiation===

Pyramidal specification occurs during early development of the cerebrum. [[Progenitor cells]] are committed to the neuronal lineage in the subcortical proliferative [[ventricular zone]] (VZ) and the [[subventricular zone]] (SVZ). Immature pyramidal cells undergo migration to occupy the [[cortical plate]], where they further diversify. [[Endocannabinoids]] (eCBs) are one class of molecules that have been shown to direct pyramidal cell development and axonal pathfinding.<ref>{{cite journal | vauthors = Mulder J, Aguado T, Keimpema E, Barabás K, Ballester Rosado CJ, Nguyen L, Monory K, Marsicano G, Di Marzo V, Hurd YL, Guillemot F, Mackie K, Lutz B, Guzmán M, Lu HC, Galve-Roperh I, Harkany T | display-authors = 6 | title = Endocannabinoid signaling controls pyramidal cell specification and long-range axon patterning | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 105 | issue = 25 | pages = 8760–8765 | date = June 2008 | pmid = 18562289 | pmc = 2438381 | doi = 10.1073/pnas.0803545105 | doi-access = free | bibcode = 2008PNAS..105.8760M }}</ref> [[Transcription factors]] such as Ctip2 and Sox5 have been shown to contribute to the direction in which pyramidal neurons direct their axons.<ref>{{cite journal | vauthors = Fishell G, Hanashima C | title = Pyramidal neurons grow up and change their mind | journal = Neuron | volume = 57 | issue = 3 | pages = 333–338 | date = February 2008 | pmid = 18255026 | doi = 10.1016/j.neuron.2008.01.018 | s2cid = 15095100 | doi-access = free }}</ref>

===Early postnatal development===

Pyramidal cells in rats have been shown to undergo many rapid changes during early [[postnatal]] life. Between postnatal days 3 and 21, pyramidal cells have been shown to double the size of the soma, increase the length of the apical dendrite fivefold, and increase basal dendrite length thirteen-fold. Other changes include the lowering of the membrane's [[resting potential]], reduction of membrane resistance, and an increase in the peak values of [[action potential]]s.<ref>{{cite journal | vauthors = Zhang ZW | title = Maturation of layer V pyramidal neurons in the rat prefrontal cortex: intrinsic properties and synaptic function | journal = Journal of Neurophysiology | volume = 91 | issue = 3 | pages = 1171–1182 | date = March 2004 | pmid = 14602839 | doi = 10.1152/jn.00855.2003 }}</ref>

==Signaling==

Like dendrites in most other neurons, the dendrites are generally the input areas of the neuron, while the axon is the neuron's output. Both axons and dendrites are highly branched. The large amount of branching allows the neuron to send and receive signals to and from many different neurons.

Pyramidal neurons, like other neurons, have numerous [[voltage-gated ion channel]]s. In pyramidal cells, there is an abundance of Na<sup>+</sup>, Ca<sup>2+</sup>, and K<sup>+</sup> channels in the dendrites, and some channels in the soma.<ref name="Spruston2008">{{cite journal | vauthors = Spruston N | title = Pyramidal neurons: dendritic structure and synaptic integration | journal = Nature Reviews. Neuroscience | volume = 9 | issue = 3 | pages = 206–221 | date = March 2008 | pmid = 18270515 | doi = 10.1038/nrn2286 | s2cid = 1142249 }}</ref><ref name="Georgiev2020">{{cite journal | vauthors = Georgiev DD, Kolev SK, Cohen E, Glazebrook JF | title = Computational capacity of pyramidal neurons in the cerebral cortex | journal = Brain Research | volume = 1748 | pages = 147069 | date = December 2020 | pmid = 32858030 | doi = 10.1016/j.brainres.2020.147069 | arxiv = 2009.10615 | s2cid = 221277603 }}</ref> Ion channels within pyramidal cell dendrites have different properties from the same ion channel type within the pyramidal cell soma.<ref name="Golding2005">{{cite journal | vauthors = Golding NL, Mickus TJ, Katz Y, Kath WL, Spruston N | title = Factors mediating powerful voltage attenuation along CA1 pyramidal neuron dendrites | journal = The Journal of Physiology | volume = 568 | issue = Pt 1 | pages = 69–82 | date = October 2005 | pmid = 16002454 | pmc = 1474764 | doi = 10.1113/jphysiol.2005.086793 }}</ref><ref name="Remy2010">{{cite journal | vauthors = Remy S, Beck H, Yaari Y | title = Plasticity of voltage-gated ion channels in pyramidal cell dendrites | journal = Current Opinion in Neurobiology | volume = 20 | issue = 4 | pages = 503–509 | date = August 2010 | pmid = 20691582 | doi = 10.1016/j.conb.2010.06.006 | s2cid = 4713853 }}</ref> Voltage-gated Ca<sup>2+</sup> channels in pyramidal cell dendrites are activated by subthreshold [[Excitatory postsynaptic potential|EPSP]]s and by [[Neural backpropagation|back-propagating]] action potentials. The extent of back-propagation of action potentials within pyramidal dendrites depends upon the K<sup>+</sup> channels. K<sup>+</sup> channels in pyramidal cell dendrites provide a mechanism for controlling the amplitude of action potentials.<ref name = "Magee">{{cite journal | vauthors = Magee J, Hoffman D, Colbert C, Johnston D | title = Electrical and calcium signaling in dendrites of hippocampal pyramidal neurons | journal = Annual Review of Physiology | volume = 60 | issue = 1 | pages = 327–346 | year = 1998 | pmid = 9558467 | doi = 10.1146/annurev.physiol.60.1.327 }}</ref>

The ability of pyramidal neurons to integrate information depends on the number and distribution of the synaptic inputs they receive. A single pyramidal cell receives about 30,000 excitatory inputs and 1700 inhibitory ([[IPSP]]s) inputs. Excitatory (EPSPs) inputs terminate exclusively on the dendritic spines, while inhibitory (IPSPs) inputs terminate on dendritic shafts, the soma, and even the axon. Pyramidal neurons can be excited by the [[neurotransmitter]] [[glutamate]],<ref name="Megias" /><ref>{{Citation|last1=Wong|first1=R. K. S.|title=NETWORKS {{!}} Cellular Properties and Synaptic Connectivity of CA3 Pyramidal Cells: Mechanisms for Epileptic Synchronization and Epileptogenesis|date=2009-01-01|url=http://www.sciencedirect.com/science/article/pii/B9780123739612002150|encyclopedia=Encyclopedia of Basic Epilepsy Research|pages=815–819|editor-last=Schwartzkroin|editor-first=Philip A.|place=Oxford|publisher=Academic Press|language=en|doi=10.1016/b978-012373961-2.00215-0|isbn=978-0-12-373961-2|access-date=2020-11-18|last2=Traub|first2=R. D.|url-access=subscription}}</ref> and inhibited by the neurotransmitter [[GABA]].<ref name = "Megias" />
[[File:Layer_V_Pyramidal_cell_from_mouse_visual_cortex.png|thumb|Synaptic inputs to a Layer V Pyramidal cell in the mouse visual cortex. Each point represents one of >&nbsp;11,000 post-synaptic sites on this neuron.]]

===Firing classifications===
Pyramidal neurons have been classified into different subclasses based upon their firing responses to 400-1000 millisecond current pulses. These classification are RSad, RSna, and IB neurons.

====RSad====
RSad pyramidal neurons, or adapting regular [[Biological neuron model|spiking neuron]]s, fire with individual [[action potential]]s (APs), which are followed by a [[Hyperpolarization (biology)|hyperpolarizing]] afterpotential. The afterpotential increases in duration which creates [[Action potential|spike frequency]] [[Neural adaptation|adaptation]] (SFA) in the neuron.<ref name = "Frances">{{cite journal | vauthors = Franceschetti S, Sancini G, Panzica F, Radici C, Avanzini G | title = Postnatal differentiation of firing properties and morphological characteristics in layer V pyramidal neurons of the sensorimotor cortex | journal = Neuroscience | volume = 83 | issue = 4 | pages = 1013–1024 | date = April 1998 | pmid = 9502243 | doi = 10.1016/S0306-4522(97)00463-6 | s2cid = 6986307 }}</ref>

====RSna====
RSna pyramidal neurons, or non-adapting regular spiking neurons, fire a train of action potentials after a pulse. These neurons show no signs of adaptation.<ref name="Frances" />

====IB====
IB pyramidal neurons, or intrinsically bursting neurons, respond to [[Threshold potential|threshold]] pulses with a burst of two to five rapid action potentials. IB pyramidal neurons show no adaptation.<ref name="Frances" />

=== Molecular classifications ===
There are several studies showing that morphological and electric pyramidal cells properties could be deduced from gene expression measured by [[single cell sequencing]].<ref name="Berg 151–158">{{cite journal | vauthors = Berg J, Sorensen SA, Ting JT, Miller JA, Chartrand T, Buchin A, Bakken TE, Budzillo A, Dee N, Ding SL, Gouwens NW, Hodge RD, Kalmbach B, Lee C, Lee BR, Alfiler L, Baker K, Barkan E, Beller A, Berry K, Bertagnolli D, Bickley K, Bomben J, Braun T, Brouner K, Casper T, Chong P, Crichton K, Dalley R, de Frates R, Desta T, Lee SD, D'Orazi F, Dotson N, Egdorf T, Enstrom R, Farrell C, Feng D, Fong O, Furdan S, Galakhova AA, Gamlin C, Gary A, Glandon A, Goldy J, Gorham M, Goriounova NA, Gratiy S, Graybuck L, Gu H, Hadley K, Hansen N, Heistek TS, Henry AM, Heyer DB, Hill D, Hill C, Hupp M, Jarsky T, Kebede S, Keene L, Kim L, Kim MH, Kroll M, Latimer C, Levi BP, Link KE, Mallory M, Mann R, Marshall D, Maxwell M, McGraw M, McMillen D, Melief E, Mertens EJ, Mezei L, Mihut N, Mok S, Molnar G, Mukora A, Ng L, Ngo K, Nicovich PR, Nyhus J, Olah G, Oldre A, Omstead V, Ozsvar A, Park D, Peng H, Pham T, Pom CA, Potekhina L, Rajanbabu R, Ransford S, Reid D, Rimorin C, Ruiz A, Sandman D, Sulc J, Sunkin SM, Szafer A, Szemenyei V, Thomsen ER, Tieu M, Torkelson A, Trinh J, Tung H, Wakeman W, Waleboer F, Ward K, Wilbers R, Williams G, Yao Z, Yoon JG, Anastassiou C, Arkhipov A, Barzo P, Bernard A, Cobbs C, de Witt Hamer PC, Ellenbogen RG, Esposito L, Ferreira M, Gwinn RP, Hawrylycz MJ, Hof PR, Idema S, Jones AR, Keene CD, Ko AL, Murphy GJ, Ng L, Ojemann JG, Patel AP, Phillips JW, Silbergeld DL, Smith K, Tasic B, Yuste R, Segev I, de Kock CP, Mansvelder HD, Tamas G, Zeng H, Koch C, Lein ES | display-authors = 6 | title = Human neocortical expansion involves glutamatergic neuron diversification | journal = Nature | volume = 598 | issue = 7879 | pages = 151–158 | date = October 2021 | pmid = 34616067 | pmc = 8494638 | doi = 10.1038/s41586-021-03813-8 | bibcode = 2021Natur.598..151B }}</ref> Several studies are proposing that single cell classifications in mouse<ref>{{cite journal | vauthors = Gouwens NW, Sorensen SA, Berg J, Lee C, Jarsky T, Ting J, Sunkin SM, Feng D, Anastassiou CA, Barkan E, Bickley K, Blesie N, Braun T, Brouner K, Budzillo A, Caldejon S, Casper T, Castelli D, Chong P, Crichton K, Cuhaciyan C, Daigle TL, Dalley R, Dee N, Desta T, Ding SL, Dingman S, Doperalski A, Dotson N, Egdorf T, Fisher M, de Frates RA, Garren E, Garwood M, Gary A, Gaudreault N, Godfrey K, Gorham M, Gu H, Habel C, Hadley K, Harrington J, Harris JA, Henry A, Hill D, Josephsen S, Kebede S, Kim L, Kroll M, Lee B, Lemon T, Link KE, Liu X, Long B, Mann R, McGraw M, Mihalas S, Mukora A, Murphy GJ, Ng L, Ngo K, Nguyen TN, Nicovich PR, Oldre A, Park D, Parry S, Perkins J, Potekhina L, Reid D, Robertson M, Sandman D, Schroedter M, Slaughterbeck C, Soler-Llavina G, Sulc J, Szafer A, Tasic B, Taskin N, Teeter C, Thatra N, Tung H, Wakeman W, Williams G, Young R, Zhou Z, Farrell C, Peng H, Hawrylycz MJ, Lein E, Ng L, Arkhipov A, Bernard A, Phillips JW, Zeng H, Koch C | display-authors = 6 | title = Classification of electrophysiological and morphological neuron types in the mouse visual cortex | journal = Nature Neuroscience | volume = 22 | issue = 7 | pages = 1182–1195 | date = July 2019 | pmid = 31209381 | pmc = 8078853 | doi = 10.1038/s41593-019-0417-0 }}</ref> and human<ref>{{cite journal | vauthors = Bakken TE, Jorstad NL, Hu Q, Lake BB, Tian W, Kalmbach BE, Crow M, Hodge RD, Krienen FM, Sorensen SA, Eggermont J, Yao Z, Aevermann BD, Aldridge AI, Bartlett A, Bertagnolli D, Casper T, Castanon RG, Crichton K, Daigle TL, Dalley R, Dee N, Dembrow N, Diep D, Ding SL, Dong W, Fang R, Fischer S, Goldman M, Goldy J, Graybuck LT, Herb BR, Hou X, Kancherla J, Kroll M, Lathia K, van Lew B, Li YE, Liu CS, Liu H, Lucero JD, Mahurkar A, McMillen D, Miller JA, Moussa M, Nery JR, Nicovich PR, Niu SY, Orvis J, Osteen JK, Owen S, Palmer CR, Pham T, Plongthongkum N, Poirion O, Reed NM, Rimorin C, Rivkin A, Romanow WJ, Sedeño-Cortés AE, Siletti K, Somasundaram S, Sulc J, Tieu M, Torkelson A, Tung H, Wang X, Xie F, Yanny AM, Zhang R, Ament SA, Behrens MM, Bravo HC, Chun J, Dobin A, Gillis J, Hertzano R, Hof PR, Höllt T, Horwitz GD, Keene CD, Kharchenko PV, Ko AL, Lelieveldt BP, Luo C, Mukamel EA, Pinto-Duarte A, Preissl S, Regev A, Ren B, Scheuermann RH, Smith K, Spain WJ, White OR, Koch C, Hawrylycz M, Tasic B, Macosko EZ, McCarroll SA, Ting JT, Zeng H, Zhang K, Feng G, Ecker JR, Linnarsson S, Lein ES | display-authors = 6 | title = Comparative cellular analysis of motor cortex in human, marmoset and mouse | journal = Nature | volume = 598 | issue = 7879 | pages = 111–119 | date = October 2021 | pmid = 34616062 | pmc = 8494640 | doi = 10.1038/s41586-021-03465-8 | bibcode = 2021Natur.598..111B }}</ref> neurons based on gene expression could explain various neuronal properties . Neuronal types in these classifications are split into excitatory, inhibitory and hundreds of corresponding sub-types. For example, pyramidal cells of layer 2-3 in human are classified as FREM3 type<ref name="Berg 151–158"/> and often have a high amount of Ih-current<ref>{{cite journal | vauthors = Kalmbach BE, Buchin A, Long B, Close J, Nandi A, Miller JA, Bakken TE, Hodge RD, Chong P, de Frates R, Dai K, Maltzer Z, Nicovich PR, Keene CD, Silbergeld DL, Gwinn RP, Cobbs C, Ko AL, Ojemann JG, Koch C, Anastassiou CA, Lein ES, Ting JT | display-authors = 6 | title = h-Channels Contribute to Divergent Intrinsic Membrane Properties of Supragranular Pyramidal Neurons in Human versus Mouse Cerebral Cortex | journal = Neuron | volume = 100 | issue = 5 | pages = 1194–1208.e5 | date = December 2018 | pmid = 30392798 | pmc = 6447369 | doi = 10.1016/j.neuron.2018.10.012 | s2cid = 53218514 | doi-access = free }}</ref> generated by [[HCN channel|HCN-channel]].

== Function ==

===Corticospinal tract===

Pyramidal neurons are the primary neural cell type in the [[corticospinal tract]]. Normal motor control depends on the development of connections between the axons in the corticospinal tract and the spinal cord. Pyramidal cell axons follow cues such as growth factors to make specific connections. With proper connections, pyramidal cells take part in the circuitry responsible for vision guided motor function.<ref>{{cite journal | vauthors = Salimi I, Friel KM, Martin JH | title = Pyramidal tract stimulation restores normal corticospinal tract connections and visuomotor skill after early postnatal motor cortex activity blockade | journal = The Journal of Neuroscience | volume = 28 | issue = 29 | pages = 7426–7434 | date = July 2008 | pmid = 18632946 | pmc = 2567132 | doi = 10.1523/JNEUROSCI.1078-08.2008 }}</ref>

===Cognition===

Pyramidal neurons in the prefrontal cortex are implicated in cognitive ability. In mammals, the complexity of pyramidal cells increases from [[Posterior (anatomy)|posterior]] to [[anterior]] brain regions. The degree of complexity of pyramidal neurons is likely linked to the cognitive capabilities of different anthropoid species. Pyramidal cells within the prefrontal cortex appear to be responsible for processing input from the primary auditory cortex, primary somatosensory cortex, and primary visual cortex, all of which process sensory modalities.<ref>{{cite journal | vauthors = Baker A, Kalmbach B, Morishima M, Kim J, Juavinett A, Li N, Dembrow N | title = Specialized Subpopulations of Deep-Layer Pyramidal Neurons in the Neocortex: Bridging Cellular Properties to Functional Consequences | journal = The Journal of Neuroscience | volume = 38 | issue = 24 | pages = 5441–5455 | date = June 2018 | pmid = 29798890 | doi = 10.1523/JNEUROSCI.0150-18.2018 | pmc = 6001033 }}</ref> These cells might also play a critical role in complex object recognition within the visual processing areas of the cortex.<ref name = "Elston" /> Relative to other species, the larger cell size and complexity of pyramidal neurons, along with certain patterns of cellular organization and function, correlates with the evolution of human cognition. <ref>{{cite journal | vauthors = Galakhova AA, Hunt S, Wilbers R, Heyer DB, de Kock CP, Mansvelder HD, Goriounova NA | title = Evolution of cortical neurons supporting human cognition | language = English | journal = Trends in Cognitive Sciences | volume = 26 | issue = 11 | pages = 909–922 | date = November 2022 | pmid = 36117080 | pmc = 9561064 | doi = 10.1016/j.tics.2022.08.012 }}</ref>

=== Memory and learning ===
The hippocampus's pyramidal cells are essential for certain types of memory and learning. They form synapses that aid in the integration of synaptic voltages throughout their complex dendritic trees through interactions with [[Mossy fiber (hippocampus)|mossy fibers]] from [[Granule cell|granule cells]]. Since it affects the postsynaptic voltages produced by mossy fiber activation, the placement of [[thorny excrescence]]s on basal and apical dendrites is important for memory formation. By enabling dynamic control of the sensitivity of CA3 pyramidal cells, this clustering of mossy fiber synapses on pyramidal cells may facilitate the initiation of somatic spikes.

The interactions between pyramidal cells and an estimated 41 mossy fiber boutons, each originating from a unique granule cell, highlight the role of these boutons in information processing and synaptic connectivity, which are essential for memory and learning. Fundamentally, mossy fiber input is received by pyramidal cells in the hippocampus which integrate synaptic voltages within their dendritic architecture. The location of prickly protrusions and the clustering of synapses influence sensitivity and contribute to the processing of information pertaining to memory and learning.<ref>{{Cite journal |last1=Gonzales |first1=R. B. |last2=DeLeon Galvan |first2=C. J. |last3=Rangel |first3=Y. M. |last4=Claiborne |first4=B. J. |date=2001-02-12 |title=Distribution of thorny excrescences on CA3 pyramidal neurons in the rat hippocampus |url=https://pubmed.ncbi.nlm.nih.gov/11169473/ |journal=The Journal of Comparative Neurology |volume=430 |issue=3 |pages=357–368 |doi=10.1002/1096-9861(20010212)430:3<357::aid-cne1036>3.0.co;2-k |issn=0021-9967 |pmid=11169473}}</ref>

== See also ==
* [[Pyramidal tract]]
* [[Chandelier cell]]s - innervate initial segments of pyramidal axons
* [[Rosehip neuron]]

== References ==
{{Reflist|30em}}

== External links ==
* [http://ccdb.ucsd.edu/sand/main?mpid=51&event=displaySum Pyramidal cell - Cell Centered Database]
* [https://web.archive.org/web/20180526085757/http://static.howstuffworks.com/gif/brain-neuron-types.gif Diagram] 
* [https://wayback.archive-it.org/all/20081217005702/http://neuromedia.neurobio.ucla.edu/campbell/nervous/wp_images%5C198_pyramidal_cells.gif Image]
* [http://www.trinity.edu/rblyston/MicroA/Lectures/L16pt1-html/sld007.htm Diagram (as part of slideshow)] {{Webarchive|url=https://web.archive.org/web/20161102003448/http://www.trinity.edu/rblyston/MicroA/Lectures/L16pt1-html/sld007.htm |date=2016-11-02 }}

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[[Category:Cerebral cortex]]
[[Category:Hippocampus (brain)]]
[[Category:Amygdala]]
[[Category:Central nervous system neurons]]
[[Category:Neurons]]