Editing Claustrum (section)

=== Microanatomy ===
Inputs to the claustrum are organized by modality, which include prefrontal, visual, auditory and [[Somatomotor system|somatomotor]] processing areas. In the same way that the morphology of neurons in the [[Rexed laminae]] of the [[spinal cord]] is indicative of function, the visual, auditory and somatomotor regions within the claustrum share similar neurons with specific functional characteristics. For example, the portion of the claustrum that processes visual information (''primarily synthesizing afferent fibers concerned with our peripheral visual field'') is comprised by a majority of binocular cells that have "elongated receptive fields and no orientation selectivity".<ref name="Smith2010">{{cite journal | vauthors = Smith JB, Alloway KD | title = Functional specificity of claustrum connections in the rat: interhemispheric communication between specific parts of motor cortex | journal = The Journal of Neuroscience | volume = 30 | issue = 50 | pages = 16832–44 | date = December 2010 | pmid = 21159954 | pmc = 3010244 | doi = 10.1523/JNEUROSCI.4438-10.2010 }}</ref><ref>{{cite journal | vauthors = Smith JB, Alloway KD | title = Interhemispheric claustral circuits coordinate sensory and motor cortical areas that regulate exploratory behaviors | journal = Frontiers in Systems Neuroscience | volume = 8 | pages = 93 | date = 2014 | pmid = 24904315 | pmc = 4032913 | doi = 10.3389/fnsys.2014.00093 | doi-access = free }}</ref>

This focus on the peripheral sensory system is not an isolated occurrence, as most sensory afferents entering the claustrum bring peripheral sensory information. Moreover, the claustrum possesses a distinct [[Topology|topological]] organization for each sensory modality as well as the dense connectivity it shares with frontal cortices.<ref name="Shelton-2022" /><ref name="Marriott-2021">{{Cite journal |last1=Marriott |first1=Brian A. |last2=Do |first2=Alison D. |last3=Zahacy |first3=Ryan |last4=Jackson |first4=Jesse |date=2021 |title=Topographic gradients define the projection patterns of the claustrum core and shell in mice |journal=Journal of Comparative Neurology |language=en |volume=529 |issue=7 |pages=1607–1627 |doi=10.1002/cne.25043 |issn=0021-9967 |pmc=8048916 |pmid=32975316}}</ref> For example, there is a retinotopic organization within the visual processing area of the claustrum that mirrors that of visual association cortices and V1, in a similar (yet less complicated) manner to the retinotopic conservation within the lateral geniculate nucleus.<ref name="Goll2015" />

Within the claustrum, local connectivity is dominated by feed-forward disynaptic inhibition wherein [[parvalbumin]]-expressing interneurons suppress the activity of nearby projection neurons.<ref>{{Cite journal |last1=Kim |first1=Juhyun |last2=Matney |first2=Chanel J. |last3=Roth |first3=Richard H. |last4=Brown |first4=Solange P. |date=2016-01-20 |title=Synaptic Organization of the Neuronal Circuits of the Claustrum |url=https://www.jneurosci.org/content/36/3/773 |journal=Journal of Neuroscience |language=en |volume=36 |issue=3 |pages=773–784 |doi=10.1523/JNEUROSCI.3643-15.2016 |issn=0270-6474 |pmid=26791208|pmc=4719014 }}</ref> Local interneurons themselves are connected through both [[Synapse|chemical]] and [[Gap junction|electrical synapses]], allowing for widespread and synchronous inhibition of local claustrum circuitry. In recent studies of the claustrum in [[mice]]<ref name="Shelton-2022" /> and [[bat]]s,<ref>{{Cite journal |last=Orman |first=Rena |date=2015-11-01 |title=Claustrum: a case for directional, excitatory, intrinsic connectivity in the rat |journal=The Journal of Physiological Sciences |language=en |volume=65 |issue=6 |pages=533–544 |doi=10.1007/s12576-015-0391-6 |pmid=26329935 |s2cid=255605784 |issn=1880-6562|doi-access=free |pmc=10717944 }}</ref> cortically-projecting excitatory claustrum neurons were found to form synapses across the anteroposterior axis and were biased toward neurons that do not share projection targets, with the possible function of joining the activity of different afferent modules.<ref name="Marriott-2021" /> Combined, these two circuits suggest that the claustrum is capable of performing local transformations of diverse input information from across the brain.