View source for Brodmann area 10

{{Short description|Brain area}}
{{Infobox brain
| Name            = Brodmann area 10
| Latin           = area frontopolaris
| Image           = Brodmann area 10.png
| Width           = 250
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| Image2          = Brodmann Cytoarchitectonics 10.png
| Caption2        =
| IsPartOf        =
| Components      =
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}}
'''Brodmann area 10''' ('''BA10''', '''frontopolar prefrontal cortex''', '''rostrolateral prefrontal cortex''', or '''anterior prefrontal cortex''') is the anterior-most portion of the [[prefrontal cortex]] in the [[human brain]].<ref>{{cite journal|last=Knowlton|first=Barbara J.|author2=Morrison, Robert G. |author3=Hummel, John E. |author4= Holyoak, Keith J. |title=A neurocomputational system for relational reasoning|journal=Trends in Cognitive Sciences|date=July 2012|volume=16|issue=7|pages=373–381|doi=10.1016/j.tics.2012.06.002 |pmid=22717468|s2cid=9968764}}</ref> BA10 was originally defined broadly in terms of its [[cytoarchitecture|cytoarchitectonic]] traits as they were observed in the brains of cadavers, but because modern [[functional imaging]] cannot precisely identify these boundaries, the terms '''anterior prefrontal cortex''', '''rostral prefrontal cortex''' and '''frontopolar prefrontal cortex''' are used to refer to the area in the most anterior part of the frontal cortex that approximately covers BA10—simply to emphasize the fact that BA10 does not include ''all'' parts of the prefrontal cortex.

BA10 is the largest cytoarchitectonic area in the human brain. It has been described as "one of the least well understood regions of the human brain".<ref name="Ramnani04"/> Present research suggests that it is involved in [[strategic]] processes in [[recall (memory)|memory recall]] and various [[executive functions]]. During  [[human evolution]], the functions in this area resulted in its expansion relative to the rest of the brain.<ref name="Semendeferi01">{{cite journal | last1 = Semendeferi | first1 = K | last2 = Armstrong | first2 = E | last3 = Schleicher | first3 = A | last4 = Zilles | first4 = K | last5 = Van Hoesen | first5 = GW | year = 2001 | title = Prefrontal cortex in humans and apes: a comparative study of area 10 | journal = Am J Phys Anthropol | volume = 114 | issue = 3| pages = 224–41 | doi = 10.1002/1096-8644(200103)114:3<224::AID-AJPA1022>3.0.CO;2-I | pmid = 11241188 | doi-access = free }}</ref>

==Anatomy==

===Size ===
The volume of the human BA10 is about 14&nbsp;cm<sup>3</sup> and constitutes roughly 1.2% of total brain volume. This is twice what would be expected in a [[hominoid]] with a human-sized brain. By comparison, the volume of BA10 in [[bonobo]]s is about 2.8&nbsp;cm<sup>3</sup>, and makes up only 0.74% of its brain volume. In each hemisphere, area 10 contains an estimated 250 million neurons.<ref name="Semendeferi01"/>

===Location===
BA10 is a subdivision of the [[cytoarchitecture|cytoarchitecturally]] defined frontal region of cerebral cortex. It occupies the most rostral portions of the [[superior frontal gyrus]] and the [[middle frontal gyrus]]. In humans, on the medial aspect of the hemisphere it is bounded ventrally by the superior rostral sulcus. It does not extend as far as the [[cingulate sulcus]]. Cytoarchitecturally it is bounded dorsally by the [[granular frontal area 9]], caudally by the [[middle frontal area 46]], and ventrally by the [[orbital area 47]] and by the [[rostral area 12]] or, in an early version of Brodmann's cortical map (Brodmann-1909), the prefrontal [[Brodmann area 11]]-1909.<ref>{{CC-notice|cc=by3|url=http://braininfo.rprc.washington.edu/centraldirectory.aspx?ID=2405}} {{Cite web |url=http://braininfo.rprc.washington.edu/centraldirectory.aspx?ID=2405 |title=BrainInfo |access-date=2013-12-03 |archive-url=https://web.archive.org/web/20131210144913/http://braininfo.rprc.washington.edu/centraldirectory.aspx?ID=2405 |archive-date=2013-12-10 |url-status=bot: unknown }}</ref>

Area 10 lies underneath the air filled [[frontal sinus]] of the skull, which has limited [[electrophysiology]] research until 2009.<ref>{{cite journal | last1 = Wallis | first1 = JD | year = 2010 | title = Polar exploration | journal = Nat Neurosci | volume = 13 | issue = 1| pages = 7–8 | doi = 10.1038/nn0110-7 | pmid = 20033080 | s2cid = 205428714 }}</ref>

===Relation to frontal pole ===
In humans the frontal pole area of the prefrontal cortex includes not only area 10 but part of BA 9. BA 10 also extends beyond the pole area into its ventromedial side. In [[Guenon]] monkeys, the pole area is filled by BA 12 (and its BA 10 is found in the orbital prefrontal region).<ref name="Ramnani04"/>

===Cytoarchitecture===

In humans the six cortical layers of area 10 have been described as having a "remarkably homogeneous appearance".<ref name="Semendeferi01"/> All of them are readily identified. Relative to each other, layer I is thin to medium in width making up 11% of the depth of area 10. Layer II is thin and contains small granular and pyramidal medium to dark staining cells (in terms of [[Franz Nissl#Named histology concepts|Nissl staining]]) which colors [[RNA]] and [[DNA]]. The widest layer is III. Its pyramidal neurons are smaller nearer the above layer II than the below layer IV. Like layer II its cells are medium to dark. Layers II and III make up 43% of the cortex depth. Layer IV has clear borders with layers III above and V below and it is thin. Its cells are pale to medium in staining. Layer V is wide and contains two distinct sublayers, Va and Vb. The density of cells Va is greater than in Vb and have darker staining. Layers IV and V make up 40% of cortical thickness. Layer VI below layer V and above the white matter contains dark pyramidal and fusiform neurons. It contributes 6% of area 10 thickness.<ref name="Semendeferi01"/>

Area 10 differs from the adjacent Brodmann 9 in that the latter has a more distinct layer Vb and more prominent layer II. Neighbouring Brodmann area 11 compared to area 10 has a thinner layer IV with more prominent layers Va, Vb and II.<ref name="Semendeferi01"/>

Area 10 in humans has the lowest neuron density among primate brains.<ref name="Semendeferi01"/> It is also unusual in that its neurons have particularly extensive [[wikt:dendritic|dendritic]] arborization and are highly dense with [[dendritic spines]].<ref>{{cite journal | last1 = Jacobs | first1 = B | last2 = Schall | first2 = M | last3 = Prather | first3 = M | last4 = Kapler | first4 = E | last5 = Driscoll | first5 = L | last6 = Baca | first6 = S | last7 = Jacobs | first7 = J | last8 = Ford | first8 = K | last9 = Wainwright | first9 = M | last10 = Treml | first10 = M | year = 2001 | title = Regional dendritic and spine variation in human cerebral cortex: a quantitative golgi study | journal = Cereb Cortex | volume = 11 | issue = 6| pages = 558–71 | doi = 10.1093/cercor/11.6.558 | pmid = 11375917 | doi-access = free }}</ref>  This situation has been suggested to enable integration of inputs from multiple areas.<ref name="Ramnani04">{{cite journal | last1 = Ramnani | first1 = N | last2 = Owen | first2 = AM | year = 2004 | title = Anterior prefrontal cortex: insights into function from anatomy and neuroimaging | journal = Nat Rev Neurosci | volume = 5 | issue = 3| pages = 184–94 | doi = 10.1038/nrn1343 | pmid = 14976518 | s2cid = 7353854 }}</ref>

===Subareas===
BA 10 is divided into three sub-areas, 10p, 10m and 10r. 10p
occupies the frontal pole while the other two cover the ventromedial part of the prefrontal cortex.<ref name="Ongür"/> Area 10m has thin layers II and IV and a more prominent layer V. In contrast, area 10r has a prominent layer II and a thicker layer IV. Large pyramidal cells are also present in 10r layer III and even more so in area 10p. But it is noted that the  "differences between the three
areas are gradual, however, and it is difficult to draw sharp boundaries between them".<ref name="Ongür">{{cite journal | last1 = Ongür | first1 = D | last2 = Ferry | first2 = AT | last3 = Price | first3 = JL | year = 2003 | title = Architectonic subdivision of the human orbital and medial prefrontal cortex | journal = J Comp Neurol | volume = 460 | issue = 3| pages = 425–49 | doi = 10.1002/cne.10609 | pmid = 12692859 | s2cid = 9798173 }}</ref> Medial frontopolar (Area 10m) cortex also contains fewer parvalbumin- and calbindin-immunoreactive neurons relative to other frontal lobe regions, especially Area 14 in orbitofrontal cortex and Area 46 in PFC.<ref name="Hogeveen">{{cite journal | last1 = Hogeveen | first1 = J | last2 = Medalla | first2 = M | last3 = Ainsworth | first3 = M | year = 2022 | title = What Does the Frontopolar Cortex Contribute to Goal-Directed Cognition and Action? | journal = J Neurosci | volume = 42 | issue = 45| pages = 8508–8513 | doi = 10.1523/JNEUROSCI.1143-22.2022 | pmid = 36351824| s2cid = 253421207 | pmc = 9665930 }}</ref>

===Connections===
Research upon primates suggests that area 10 has inputs and output connections with other higher-order association cortex areas particularly in the prefrontal cortex while having few with primary sensory or motor areas. Its connections through the [[extreme capsule]] link it to the auditory and multisensory areas of the [[superior temporal sulcus]]. They also continue in the [[medial longitudinal fasciculus]] in the white matter of the superior temporal gyrus areas on the superior temporal gyrus (areas TAa, TS2, and TS3) and nearby multisensory areas on the upper bank of the superior temporal sulcus (TPO). Another area connected through the extreme capsule is the ventral region of the [[Insular cortex|insula]]. Connections through the [[cingulate fasciculus]] link area 10 to the [[anterior cingulate cortex|anterior]], [[posterior cingulate cortex]], and [[retrosplenial cortex]]. The [[uncinate fasciculus]] connects it with the [[amygdala]], temporopolar [[proisocortex]] and anterior most part of the superior temporal gyrus. There are no connections to the [[parietal cortex]], [[occipital cortex]] nor [[inferotemporal cortex]]<ref name="Petrides07">{{cite journal | last1 = Petrides | first1 = M | last2 = Pandya | first2 = DN | year = 2007 | title = Efferent association pathways from the rostral prefrontal cortex in the macaque monkey | url = http://www.jneurosci.org/cgi/reprint/27/43/11573 | journal = J Neurosci | volume = 27 | issue = 43| pages = 11573–86 | pmc=6673207|doi = 10.1523/JNEUROSCI.2419-07.2007 | pmid = 17959800 | doi-access = free }}</ref>

Its connections have been summarized as "it seems not to be interconnected with ‘downstream’ areas in the way that other prefrontal areas are. .. it is the only prefrontal region that is predominantly (and possibly exclusively) interconnected with supramodal cortex in the PFC, anterior temporal cortex and cingulate cortex."<ref name="Ramnani04"/> It has been proposed that due to this connectivity that it can "play a major role in the highest level of integration of information coming from visual, auditory, and somatic sensory systems to achieve amodal, abstract, conceptual interpretation of the environment .. and may be the anatomical basis for the suggested role of the rostral prefrontal cortex in influencing abstract information processing and the integration of the outcomes of multiple cognitive operations".<ref name="Petrides07"/>

==Evolution==

Katerina Semendeferi and colleagues has suggested that "During hominid evolution, area 10 underwent a couple of .. changes: one involves a considerable increase in overall size, and the other involves a specific increase in connectivity, especially with other higher-order association areas."<ref name="Semendeferi01"/>

[[endocast|Cranial endocast]]s taken from the inside of the skull of  ''[[Homo floresiensis]]''  show an expansion in the frontal polar region suggesting enlargement in its Brodmann's area 10.<ref>{{cite journal | last1 = Falk | first1 = D | last2 = Hildebolt | first2 = C | last3 = Smith | first3 = K | last4 = Morwood | first4 = MJ | last5 = Sutikna | first5 = T | last6 = Brown | first6 = P | last7 = Jatmiko | first7 = Saptomo EW | last8 = Brunsden | first8 = B | last9 = Prior | first9 = F | year = 2005 | title = The brain of LB1, Homo floresiensis | journal = Science | volume = 308 | issue = 5719| pages = 242–5 | doi = 10.1126/science.1109727 | pmid = 15749690 | bibcode = 2005Sci...308..242F | s2cid = 43166136 | url = http://doc.rero.ch/record/14871/files/PAL_E2009.pdf }}</ref>

==Function==
Although this region is extensive in humans, its function is poorly understood.<ref name="Semendeferi01"/>  Koechlin & Hyafil have proposed that processing of 'cognitive branching' is the core function of the frontopolar cortex.<ref>{{cite journal | last1 = Koechlin | first1 = E. | last2 = Hyafil | first2 = A. | year = 2007 | title = Anterior prefrontal function and the limits of human-decision making | journal = Science | volume = 318 | issue = 5850| pages = 594–598 | doi=10.1126/science.1142995| pmid = 17962551 | bibcode = 2007Sci...318..594K | s2cid = 7903857 }}</ref> Cognitive branching enables a previously running task to be maintained in a pending state for subsequent retrieval and execution upon completion of the ongoing one. Many of our complex behaviors and mental activities require simultaneous engagement of multiple tasks, and they suggest the anterior prefrontal cortex may perform a domain-general function in these scheduling operations. Thus, the frontopolar cortex shares features with the [[Central executive network|central executive]] in [[Baddeley's model of working memory]]. However, other hypotheses have also been proffered, such as those by Burgess ''et al.''.<ref>{{cite journal | last1 = Burgess | first1 = P.W. | last2 = Dumontheil | first2 = I. | last3 = Gilbert | first3 = S.J. | year = 2007 | title = The gateway hypothesis of rostral prefrontal cortex (area 10) function | journal = Trends in Cognitive Sciences | volume = 11 | issue = 7 | doi = 10.1016/j.tics.2007.05.004 | pmid = 17548231 | pages=290–298| citeseerx = 10.1.1.578.2743 | s2cid = 13509187 }}</ref>{{clarify|date=October 2012}} These also take into consideration the influence of the [[limbic system]], to which the frontopolar cortex is connected through the ventromedial prefrontal cortex. A 2006 meta-analysis found that the rostral prefrontal cortex was involved in working memory, episodic memory and multiple-task coordination.<ref>{{Cite journal|title = Functional specialization within rostral prefrontal cortex (area 10): a meta-analysis|journal = Journal of Cognitive Neuroscience|date = 2006-06-01|issn = 0898-929X|pmid = 16839301|pages = 932–948|volume = 18|issue = 6|doi = 10.1162/jocn.2006.18.6.932|first1 = Sam J.|last1 = Gilbert|first2 = Stephanie|last2 = Spengler|first3 = Jon S.|last3 = Simons|first4 = J. Douglas|last4 = Steele|first5 = Stephen M.|last5 = Lawrie|first6 = Christopher D.|last6 = Frith|first7 = Paul W.|last7 = Burgess|citeseerx = 10.1.1.530.7540|s2cid = 7366161}}</ref>
This area has also been implicated in decision making prior to the decision being available to conscious awareness <ref>Soon, Brass, Heinze and Haynes, 2008. Nature Neuroscience</ref>

==Images==
<gallery>
File:Brodmann area 10 animation small.gif|Animation.
File:Brodmann area 10 frontal.jpg|front view.
File:Brodmann area 10 lateral.jpg|Lateral view.
File:Brodmann area 10 medial.jpg|Medial view.
</gallery>

==See also==
* [[Brodmann area]]
* [[Cytoarchitectonics of the cerebral cortex]]
* [[List of regions in the human brain]]
* [[Prefrontal cortex]]

==References==
<references/>

==External links==
{{Commons category|Brodmann area 10}}
* {{BrainInfo|ancil|56}} - "frontopolar area 10"
* {{BrainInfo|ancil|58}} - "Brodmann area 10"
* [http://neuro.imm.dtu.dk/services/brededatabase/WOROI_46.html Brede Database Brodmann area 10] {{Webarchive|url=https://web.archive.org/web/20110719124054/http://neuro.imm.dtu.dk/services/brededatabase/WOROI_46.html |date=2011-07-19 }}
* [http://brainmaps.org/index.php?pm=area%2010%20of%20prefrontal%20cortex BrainMaps Area 10 Of Prefrontal Cortex]
* [http://questioneverything.typepad.com/question_everything/2010/04/is-brodmann-area-10-the-key-to-human-evolution.html Is Brodmann Area 10 the Key to Human Evolution?]

{{Brodmann area}}
{{Prosencephalon}}

{{DEFAULTSORT:Brodmann Area 10}}
[[Category:Brodmann areas|10]]
[[Category:Frontal lobe]]