Editing Claustrum (section)

{{Short description|Structure in the brain}}
{{Distinguish|Colostrum}}
{{Infobox Brain
|  Name            = Claustrum
|  Latin           = 
|  Image           = File:Gray 718-emphasizing-claustrum.png
|  Caption         = [[Coronal section]] of human [[cerebrum]]. The claustrum is indicated by the arrow.
|  Image2          = File:Gray742-emphasizing-claustrum.png
|  Caption2        = [[Transverse section]] of human cerebrum. (Anterior is at the top.)<br>The claustrum is indicated by the arrow.
|  IsPartOf        = [[Brain]]
|  Components      = 
|  Artery          = [[Middle cerebral artery]]
|  Vein            = 
}}
The '''claustrum''' (Latin, meaning "to close" or "to shut") is a thin sheet of [[neuron]]s and supporting [[glial cells]] in the [[brain]], that connects to the [[cerebral cortex]] and subcortical regions including the [[amygdala]], [[hippocampus]] and [[thalamus]].<ref name="Crick2005">{{cite journal | vauthors = Crick FC, Koch C | title = What is the function of the claustrum? | journal = Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences | volume = 360 | issue = 1458 | pages = 1271–9 | date = June 2005 | pmid = 16147522 | pmc = 1569501 | doi = 10.1098/rstb.2005.1661 }}</ref><ref name="Smith1">{{cite journal | vauthors = Smith JB, Lee AK, Jackson J | title = The claustrum | journal = Current Biology | volume = 30 | pages = R1401–R1406 | date = 2020 | issue = 23 | pmid = 33290700| doi= 10.1016/j.cub.2020.09.069 | s2cid = 227507231 | doi-access = free | bibcode = 2020CBio...30R1401S }}</ref> It is located between the [[insular cortex]] laterally and the [[putamen]] medially, encased by the [[Extreme capsule|extreme]] and [[external capsule]]s respectively.<ref name="Smith2019">{{cite journal |vauthors=Smith JB, Alloway KD, Hof PR, Orman R, Reser DH, Watakabe A, ((Watson GDR)) |title=The relationship between the claustrum and endopiriform nucleus: A perspective towards consensus on cross-species homology |journal=J Comp Neurol |volume=527 |issue=2 |pages=476–499 |date=February 2019 |pmid=30225888 |pmc=6421118 |doi=10.1002/cne.24537 |url=}}</ref><ref name="Crick2005" /><ref name="Chau2015">{{cite journal | vauthors = Chau A, Salazar AM, Krueger F, Cristofori I, Grafman J | title = The effect of claustrum lesions on human consciousness and recovery of function | journal = Consciousness and Cognition | volume = 36 | pages = 256–64 | date = November 2015 | pmid = 26186439 | doi = 10.1016/j.concog.2015.06.017 | s2cid = 46139982 }}</ref> Blood to the claustrum is supplied by the [[middle cerebral artery]].<ref name="Crick2005" /> It is considered to be the most densely connected structure in the brain, and thus hypothesized to allow for the integration of various cortical inputs such as vision, sound and touch, into [[Gestalt psychology|one experience]].<ref name="Chau2015" /><ref name="Brown">{{cite journal | vauthors = Brown SP, Mathur BN, Olsen SR, Luppi PH, Bickford ME, Citri A | title = New Breakthroughs in Understanding the Role of Functional Interactions between the Neocortex and the Claustrum | journal = The Journal of Neuroscience | volume = 37 | issue = 45 | pages = 10877–10881 | date = November 2017 | pmid = 29118217 | pmc = 5678020 | doi = 10.1523/JNEUROSCI.1837-17.2017 }}</ref> Other hypotheses suggest that the claustrum plays a role in [[Salience network|salience processing]], to direct attention towards the most behaviorally relevant stimuli amongst the background noise.<ref name="Smith2">{{cite journal | vauthors = Smith JB, Watson G, Liang Z, Liu Y, Zhang N, Alloway KD | title = A Role for the Claustrum in Salience Processing? | journal = Frontiers in Neuroanatomy | volume = 13 | pages = R1401–R1406 | date = 2020 | issue = 64 | pmid = 31275119| pmc= 6594418 | doi = 10.3389/fnana.2019.00064 | doi-access = free }}</ref> The claustrum is difficult to study given the limited number of individuals with claustral lesions and the poor resolution of [[neuroimaging]].

The claustrum is made up of various cell types differing in size, shape and neurochemical composition. Five cell types exist, and a majority of these cells resemble [[pyramidal neurons]] found in the cortex.<ref name="Braak">{{cite journal | vauthors = Braak H, Braak E | title = Neuronal types in the claustrum of man | journal = Anatomy and Embryology | volume = 163 | issue = 4 | pages = 447–60 | date = 1982 | pmid = 7091711 | doi = 10.1007/BF00305558 | s2cid = 7566723 }}</ref><ref name="Nikolenko2021">{{cite journal |vauthors=Nikolenko VN, Rizaeva NA, Beeraka NM, Oganesyan MV, Kudryashova VA, Dubovets AA, Borminskaya ID, Bulygin KV, Sinelnikov MY, Aliev G |title=The mystery of claustral neural circuits and recent updates on its role in neurodegenerative pathology |journal=Behav Brain Funct |volume=17 |issue=1 |pages=8 |date=July 2021 |pmid=34233707 |pmc=8261917 |doi=10.1186/s12993-021-00181-1 |url= |doi-access=free }}</ref> Within the claustrum, there is no [[laminar organization]] of cell types as in the [[Cerebral cortex#Layers|cortical layers]], and the [[Soma (biology)|cell bodies]] can be a pyramidal, fusiform or circular.<ref name="Crick2005"/> The principal cell type found in the claustrum is the [[Golgi type I]] neuron, which is a large cell with [[dendrite]]s covered in [[dendritic spine|spines]].<ref name="Mathur">{{cite journal |vauthors=Mathur BN |title=The claustrum in review |journal=Front Syst Neurosci |volume=8 |issue= |pages=48 |date=2014 |pmid=24772070 |pmc=3983483 |doi=10.3389/fnsys.2014.00048 |url= |doi-access=free }}</ref><ref name="Nikolenko2021"/>
 
Through interhemispheric connections, the claustrum is believed to play a role in synchronizing activity in widely separated, but functionally related, parts of the brain such as between [[frontal eye fields]] and the [[visual cortex]].<ref name="Crick2005" /><ref name="Smith2017">{{cite journal | vauthors = Smith JB, Liang Z, Watson GD, Alloway KD, Zhang N | title = Interhemispheric resting-state functional connectivity of the claustrum in the awake and anesthetized states | journal = Brain Structure & Function | volume = 222 | issue = 5 | pages = 2041–2058 | date = July 2017 | pmid = 27714529 | pmc = 5382132 | doi = 10.1007/s00429-016-1323-9 }}</ref><ref>{{cite journal | vauthors = Stevens CF | title = Consciousness: Crick and the claustrum | journal = Nature | volume = 435 | issue = 7045 | pages = 1040–1 | date = June 2005 | pmid = 15973394 | doi = 10.1038/4351040a | bibcode = 2005Natur.435.1040S | s2cid = 5402518 }}</ref> As such, the claustrum is thought to play a role in combining different information modalities, potentially to support consciousness itself.<ref name="Smith2017"/><ref name="Torgerson2015">{{cite journal | vauthors = Torgerson CM, Irimia A, Goh SY, Van Horn JD | title = The DTI connectivity of the human claustrum | journal = Human Brain Mapping | volume = 36 | issue = 3 | pages = 827–38 | date = March 2015 | pmid = 25339630 | pmc = 4324054 | doi = 10.1002/hbm.22667 }}</ref> Another proposed function of the claustrum is to differentiate between relevant and irrelevant information so that the latter can be ignored.<ref name="Brown" /><ref name="Torgerson2015" /><ref name="Goll2015">{{cite journal | vauthors = Goll Y, Atlan G, Citri A | title = Attention: the claustrum | journal = Trends in Neurosciences | volume = 38 | issue = 8 | pages = 486–95 | date = August 2015 | pmid = 26116988 | doi = 10.1016/j.tins.2015.05.006 | s2cid = 38353825 }}</ref>

Cortical components of [[consciousness]] include the fronto-parietal cortex, [[Cingulate cortex|cingulate]] and [[precuneus]]. Due to the claustrum's widespread connectivity to these areas, it is suggested that it may play a role in both [[attention]] and [[consciousness]]. The neural networks that mediate sustained attention and consciousness send inputs to the claustrum, and one case report in humans suggests that electrical stimulation near the claustrum reversibly disrupted the patient's conscious state.<ref name="Koubeissi-2014">{{cite journal | vauthors = Koubeissi MZ, Bartolomei F, Beltagy A, Picard F | title = Electrical stimulation of a small brain area reversibly disrupts consciousness | journal = Epilepsy & Behavior | volume = 37 | pages = 32–5 | date = August 2014 | pmid = 24967698 | doi = 10.1016/j.yebeh.2014.05.027 | s2cid = 8368944 }}</ref>