Editing Claustrum (section)

=== Cell types ===
The claustrum is made up of various cell types that differ in size, shape and neurochemical composition.<ref name="Chau2015" /> Excitatory cell types in the claustrum consist of two main classes which differentially project to [[Cortex (anatomy)|cortical]] and [[Subcortex|subcortical]] brain regions.{{Citation needed|date=September 2023}} Inhibitory neurons represent only 10%-15% of the neurons within the claustrum and consist of three types, expressing [[parvalbumin]], [[Somatostatin receptor 2|somatostatin]] or [[Vasoactive intestinal peptide receptor|vasoactive intestinal peptide]], similar to inhibitory neurons in the cortex.<ref>{{Cite journal|last1=Tremblay|first1=Robin|last2=Lee|first2=Soohyun|last3=Rudy|first3=Bernardo|date=20 July 2016|title=GABAergic interneurons in the neocortex: From cellular properties to circuits|url= |journal=Neuron|volume=91|issue=2|pages=260–292|doi=10.1016/j.neuron.2016.06.033|pmid=27477017|pmc=4980915|doi-access=free}}</ref> Finally, many studies show that the claustrum is best distinguished structurally by its prominent plexus of parvalbumin-positive fibers formed by parvalbumin-expressing inhibitory cell types.<ref name="Brown" /> In recent studies, the use of [[myelin basic protein]] (MBP) and retrogradely traveling [[cholera toxin]] have additionally been used as effective methods of identifying the claustrum.<ref name="Marriott-2021" /><ref>{{Cite journal |last1=Wang |first1=Quanxin |last2=Wang |first2=Yun |last3=Kuo |first3=Hsien-Chi |last4=Xie |first4=Peng |last5=Kuang |first5=Xiuli |last6=Hirokawa |first6=Karla E. |last7=Naeemi |first7=Maitham |last8=Yao |first8=Shenqin |last9=Mallory |first9=Matt |last10=Ouellette |first10=Ben |last11=Lesnar |first11=Phil |last12=Li |first12=Yaoyao |last13=Ye |first13=Min |last14=Chen |first14=Chao |last15=Xiong |first15=Wei |date=2023-02-28 |title=Regional and cell-type-specific afferent and efferent projections of the mouse claustrum  |journal=Cell Reports |volume=42 |issue=2 |pages=112118 |doi=10.1016/j.celrep.2023.112118 |pmid=36774552 |pmc=10415534 |issn=2211-1247 }}</ref>

Several approaches in [[mice]] have been used to assess claustrum cell types, including electrophysiological, morphological, genetic, and connectomic approaches.<ref name="Shelton-2022">{{Cite journal |last1=Shelton |first1=Andrew |last2=Oliver |first2=David |last3=Grimstvedt |first3=Joachim |last4=Lazarte |first4=Ivan |last5=Kapoor |first5=Ishaan |last6=Clifford |first6=Kentros |last7=Witter |first7=Menno |last8=Butt |first8=Simon |last9=Packer |first9=Adam |date=2022 |title=Single neurons and networks in the claustrum integrate input from widespread cortical sources |url=https://www.biorxiv.org/content/10.1101/2022.05.06.490864v1 |website=bioRxiv|doi=10.1101/2022.05.06.490864 |s2cid=248672084 }}</ref><ref name="Marriott-2021" /><ref name="Qadir-2022">{{Cite journal |last1=Qadir |first1=Houman |last2=Stewart |first2=Brent W. |last3=VanRyzin |first3=Jonathan W. |last4=Wu |first4=Qiong |last5=Chen |first5=Shuo |last6=Seminowicz |first6=David A. |last7=Mathur |first7=Brian N. |date=2022-12-20 |title=The mouse claustrum synaptically connects cortical network motifs |journal=Cell Reports |volume=41 |issue=12 |pages=111860 |doi=10.1016/j.celrep.2022.111860 |pmid=36543121 |pmc=9838879 |issn=2211-1247}}</ref><ref>{{Cite journal |last1=Graf |first1=Martin |last2=Nair |first2=Aditya |last3=Wong |first3=Kelly L. L. |last4=Tang |first4=Yanxia |last5=Augustine |first5=George J. |date=2020-07-01 |title=Identification of Mouse Claustral Neuron Types Based on Their Intrinsic Electrical Properties |url=https://www.eneuro.org/content/7/4/ENEURO.0216-20.2020 |journal=eNeuro |language=en |volume=7 |issue=4 |doi=10.1523/ENEURO.0216-20.2020 |issn=2373-2822 |pmid=32527746|pmc=7405070 }}</ref><ref>{{Cite journal |last1=Erwin |first1=Sarah R |last2=Bristow |first2=Brianna N |last3=Sullivan |first3=Kaitlin E |last4=Kendrick |first4=Rennie M |last5=Marriott |first5=Brian |last6=Wang |first6=Lihua |last7=Clements |first7=Jody |last8=Lemire |first8=Andrew L |last9=Jackson |first9=Jesse |last10=Cembrowski |first10=Mark S |date=2021-08-16 |editor-last=Mao |editor-first=Tianyi |editor2-last=Westbrook |editor2-first=Gary L |editor3-last=Zhang |editor3-first=Li I |title=Spatially patterned excitatory neuron subtypes and projections of the claustrum |journal=eLife |volume=10 |pages=e68967 |doi=10.7554/eLife.68967 |pmid=34397382 |pmc=8367382 |issn=2050-084X |doi-access=free }}</ref> While no clear consensus has yet been reached regarding the exact number of excitatory cell types, recent studies have suggested that cortically- and subcortically-projecting claustrum neurons are likely distinct and vary along several metrics, such as their intrinsic electrophysiological profiles, afferent projections, and neuromodulatory profiles.<ref name="Shelton-2022" /><ref name="Qadir-2022" /><ref>{{Cite journal |last1=Nair |first1=Aditya |last2=Teo |first2=Yue Yang |last3=Augustine |first3=George J. |last4=Graf |first4=Martin |date=2023-07-11 |title=A functional logic for neurotransmitter corelease in the cholinergic forebrain pathway |journal=Proceedings of the National Academy of Sciences |language=en |volume=120 |issue=28 |pages=e2218830120 |doi=10.1073/pnas.2218830120 |issn=0027-8424 |pmc=10334726 |pmid=37399414|bibcode=2023PNAS..12018830N }}</ref>