In mammalian brain anatomy, the prefrontal cortex (PFC) covers the front part of the

frontal lobe The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a groove b ...

of the

cerebral cortex The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting o ...

. The PFC contains the Brodmann areas BA8, BA9, BA10, BA11, BA12, BA13, BA14, BA24, BA25, BA32, BA44, BA45, BA46, and BA47. The basic activity of this brain region is considered to be orchestration of thoughts and actions in accordance with internal goals. Many authors have indicated an integral link between a person's will to live, personality, and the functions of the prefrontal cortex. This brain region has been implicated in

executive functions In cognitive science and neuropsychology, executive functions (collectively referred to as executive function and cognitive control) are a set of cognitive processes that are necessary for the cognitive control of behavior: selecting and succ ...

, such as

planning Planning is the process of thinking regarding the activities required to achieve a desired goal. Planning is based on foresight, the fundamental capacity for mental time travel. The evolution of forethought, the capacity to think ahead, is c ...

decision making In psychology, decision-making (also spelled decision making and decisionmaking) is regarded as the cognitive process resulting in the selection of a belief or a course of action among several possible alternative options. It could be either ra ...

short-term memory Short-term memory (or "primary" or "active memory") is the capacity for holding a small amount of information in an active, readily available state for a short interval. For example, short-term memory holds a phone number that has just been recit ...

, personality expression, moderating social behavior and controlling certain aspects of speech and language. Executive function relates to abilities to differentiate among conflicting thoughts, determine good and bad, better and best, same and different, future consequences of current activities, working toward a defined goal, prediction of outcomes, expectation based on actions, and social "control" (the ability to suppress urges that, if not suppressed, could lead to socially unacceptable outcomes). The frontal cortex supports concrete rule learning. More anterior regions along the rostro-caudal axis of frontal cortex support rule learning at higher levels of abstraction.

Structure

Definition

There are three possible ways to define the prefrontal cortex: * as the granular frontal cortex * as the projection zone of the medial dorsal nucleus of the

thalamus The thalamus (from Greek θάλαμος, "chamber") is a large mass of gray matter located in the dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all direction ...

* as that part of the frontal cortex whose electrical stimulation does not evoke movements

Granular frontal cortex

The prefrontal cortex has been defined based on

cytoarchitectonics Cytoarchitecture (Greek '' κύτος''= "cell" + '' ἀρχιτεκτονική''= "architecture"), also known as cytoarchitectonics, is the study of the cellular composition of the central nervous system's tissues under the microscope. Cytoarchi ...

by the presence of a cortical granular layer IV. It is not entirely clear who first used this criterion. Many of the early cytoarchitectonic researchers restricted the use of the term prefrontal to a much smaller region of cortex including the gyrus rectus and the gyrus rostralis ( Campbell, 1905; G. E. Smith, 1907; Brodmann, 1909; von Economo and

Koskinas Koskinas ( el, Κοσκινάς) is a village in the municipality of Olympia, Elis, Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, an ...

, 1925). In 1935, however,

Jacobsen Jacobsen may refer to: * Jacobsen (surname), including a list of people with the name * Jacobsen Manufacturing, a former American manufacturer ** Jacobsen, a brand of lawn-care products by Textron * Jacobsen Publishing, publisher of several Americ ...

used the term prefrontal to distinguish granular prefrontal areas from agranular motor and premotor areas. In terms of Brodmann areas, the prefrontal cortex traditionally includes areas 8, 9, 10, 11, 12, 13, 14, 24, 25, 32, 44, 45, 46, and 47, however, not all of these areas are strictly granular – 44 is dysgranular, caudal 11 and orbital 47 are agranular. The main problem with this definition is that it works well only in

primate Primates are a diverse order (biology), order of mammals. They are divided into the Strepsirrhini, strepsirrhines, which include the lemurs, galagos, and lorisids, and the Haplorhini, haplorhines, which include the Tarsiiformes, tarsiers and ...

s but not in nonprimates, as the latter lack a granular layer IV.

Projection zone

To define the prefrontal cortex as the projection zone of the mediodorsal nucleus of the

builds on the work of Rose and Woolsey, who showed that this nucleus projects to anterior and ventral parts of the brain in nonprimates, however, Rose and Woolsey termed this projection zone "orbitofrontal." It seems to have been Akert, who, for the first time in 1964, explicitly suggested that this criterion could be used to define homologues of the prefrontal cortex in primates and nonprimates. This allowed the establishment of homologies despite the lack of a granular frontal cortex in nonprimates. The projection zone definition is still widely accepted today (e.g. Fuster), although its usefulness has been questioned. Modern tract tracing studies have shown that projections of the mediodorsal nucleus of the thalamus are not restricted to the granular frontal cortex in primates. As a result, it was suggested to define the prefrontal cortex as the region of cortex that has stronger reciprocal connections with the mediodorsal nucleus than with any other thalamic nucleus. Uylings et al. acknowledge, however, that even with the application of this criterion, it might be rather difficult to define the prefrontal cortex unequivocally.

Electrically silent area of frontal cortex

A third definition of the prefrontal cortex is the area of frontal cortex whose electrical stimulation does not lead to observable movements. For example, in 1890 David Ferrier used the term in this sense. One complication with this definition is that the electrically "silent" frontal cortex includes both granular and non-granular areas.

Subdivisions

According to Striedter the PFC of humans can be delineated into two functionally, morphologically, and evolutionarily different regions: the ventromedial PFC (vmPFC) consisting of the ''ventral prefrontal cortex'' and the ''medial prefrontal cortex'' present in all

mammals Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fu ...

, and the

lateral prefrontal cortex In human brain anatomy, the lateral prefrontal cortex (LPFC) is part of the prefrontal cortex (PFC). According to Striedter the PFC of humans can be delineated into two functionally, morphologically, and evolutionarily different regions: the ve ...

(LPFC), consisting of the ''dorsolateral prefrontal cortex'' and the ''ventrolateral prefrontal cortex'', present only in

primates Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians (monkeys and apes, the latter includin ...

. The LPFC contains the Brodmann areas BA8, BA9, BA10, BA45, BA46, and BA47. Some researchers also include BA44. The vmPFC contains the Brodmann areas BA12, BA25, BA32, BA33, BA24, BA11, BA13, and BA14. The table below shows different ways to subdivide parts of the human prefrontal cortex based upon Brodmann areas. *The dorsolateral prefrontal cortex is composed of the BA8, BA9, BA10, and BA46. *The

ventrolateral prefrontal cortex The ventrolateral prefrontal cortex (VLPFC) is a section of the prefrontal cortex located on the inferior frontal gyrus, bounded superiorly by the inferior frontal sulcus and inferiorly by the lateral sulcus. It is attributed to the ...

is composed of areas BA45, BA47, and BA44. *The medial prefrontal cortex (mPFC) is composed of BA12, BA25, and

anterior cingulate cortex In the human brain, the anterior cingulate cortex (ACC) is the frontal part of the cingulate cortex that resembles a "collar" surrounding the frontal part of the corpus callosum. It consists of Brodmann areas 24, 32, and 33. It is involve ...

: BA32, BA33, BA24. *The ventral prefrontal cortex is composed of areas BA11, BA13, and BA14. (Also see the definition of the orbitofrontal cortex.) *The dorsolateral prefrontal cortex contains BA8, including the