Editing Precuneus (section)

== Structure ==
[[File:Precuneus connectivity new.gif|thumb|300px|Subdivisions of precuneus and posterior cingulate in the human based upon [[Default mode network|resting state]] functional connectivity.<ref name="Margulies"/>
{{Legend|#6367c5|Blue: Sensorimotor Anterior Region and its connections}}
{{Legend|#84b29c|Green: Cognitive/Associative Central Region}}
{{Legend|#c9ae73|Yellow: Visual Posterior Region}}
(The red color shows the [[posterior cingulate]] and its connections.)]]

The precuneus is located on the inside between the two [[cerebral hemisphere]]s in the rear region between the [[somatosensory|somatosensory cortex]] and forward of the [[cuneus]] (which contains the [[visual cortex]]). It is above the [[posterior cingulate]]. Following [[Korbinian Brodmann]] it has traditionally been considered a homogeneous structure and with limited distinction between it and the neighboring [[posterior cingulate]] area. Brodmann mapped it as the medial continuation of lateral parietal [[Brodmann area 7|area 7]].

[[Anterograde tracing|Axon tracing]] research on [[macaque monkey]]s has established that it consists of three subdivisions which now have been confirmed by [[fMRI]] upon  resting-state [[Functional neuroimaging|functional connectivity]] to also exist in [[human]]s (parallel fMRI research has also been done upon monkeys).<ref name="Margulies">{{cite journal |vauthors=Margulies DS, Vincent JL, Kelly C, Lohmann G, Uddin LQ, Biswal BB, Villringer A, Castellanos FX, Milham MP, Petrides M |title=Precuneus shares intrinsic functional architecture in humans and monkeys |journal=PNAS |year=2009 |doi=10.1073/pnas.0905314106 |pmid=19903877 |volume=106 |issue=47 |pages=20069–74 |pmc=2775700 |bibcode=2009PNAS..10620069M |doi-access=free }}</ref>

=== Subdivisions ===
;Sensorimotor Anterior Region
This occurs around the margin of the [[cingulate sulcus]]  ({{Legend inline|#6367c5}}blue in figure) and is connected with sensorimotor areas of the cerebral cortex such as the [[paracentral lobule]], [[supplementary motor area]], [[premotor cortex]], [[somatosensory area]] ([[Brodmann area 2]]), [[parietal operculum]] and [[insular cortex|insula]]. fMRI Research upon humans finds a connection with the caudalmost part of [[parahippocampus]] and [[superior temporal gyrus]]. No connections with the [[inferior parietal lobule]], [[prefrontal cortex]] nor [[primary motor cortex]].

;Cognitive/Associative Central Region
This occurs around the precuneal sulcus ({{Legend inline|#84b29c}}green in figure) and is connected with the [[inferior parietal lobule]] particularly the [[angular gyrus]] and prefrontal areas [[Brodmann area 10|10]], [[Brodmann area 46|46]] and [[Brodmann area 8|8]]. No connections exist with premotor, motor, or somatosensory areas. The areas with which it links are involved in [[executive functions]], [[working memory]] and [[motor planning]].

;Visual Posterior Region
This occurs along the parieto-occipital fissure ({{Legend inline|#c9ae73}}yellow in figure). This connects with visual areas in the [[cuneus]] and [[primary visual cortex]].

=== Subcortical connections ===
Below the cerebral cortex, the precuneus is connected  with the dorsalmost nuclei of the [[thalamus]], including the [[ventral lateral nucleus]], the central and anterior nuclei of the [[intralaminar nuclear group]],  and the lateral [[pulvinar nuclei|pulvinar]]. Other connections include the [[claustrum]], the dorsolateral [[caudate nucleus]], [[putamen]], and the [[zona incerta]].<ref name="Cavanna06"/><ref name="Cavanna"/> It also has links with the [[brainstem]] areas such as the [[pretectal area]], the [[superior colliculus]], the [[nucleus reticularis tegmenti pontis]], and the [[basis pontis]].<ref name="Cavanna06"/><ref name="Cavanna"/>