Brodmann area 46
Encyclopedia
Brodmann area 46, or BA46, is part of the frontal
cortex
in the human brain
. It is between BA10
and BA45
.
BA46 is known as middle frontal area 46. In the human brain it occupies approximately the middle third of the middle frontal gyrus
and the most rostral portion of the inferior frontal gyrus
. Brodmann area 46 roughly corresponds with the dorsolateral prefrontal cortex
(DLPFC), although the borders of area 46 are based on cytoarchitecture rather than function. The DLPFC also encompasses part of granular frontal area 9, directly adjacent on the dorsal surface of the cortex.
Cytoarchitecturally, BA46 is bounded dorsally by the granular frontal area 9, rostroventrally by the frontopolar area 10 and caudally by the triangular area 45 (Brodmann-1909). There is some discrepancy between the extent of BA8
(Brodmann-1905) and the same area as described by Walker (1940)
and working memory
. Lesions to the DLPFC impair short-term memory and cause difficulty inhibiting responses. Lesions may also eliminate much of the ability to make judgements about what's relevant and what's not as well as causing problems in organization.
The DLPFC has recently been found to be involved in exhibiting self-control. http://sciencenow.sciencemag.org/cgi/content/full/2009/501/3
The dorsolateral prefrontal cortex is one of the few areas deactivated during REM sleep. Neuroscientist J. Allan Hobson has hypothesized that activation of the dorsolateral prefrontal cortex produce lucid dreams.
Frontal lobe
The frontal lobe is an area in the brain of humans and other mammals, located at the front of each cerebral hemisphere and positioned anterior to the parietal lobe and superior and anterior to the temporal lobes...
cortex
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
in the human brain
Human brain
The human brain has the same general structure as the brains of other mammals, but is over three times larger than the brain of a typical mammal with an equivalent body size. Estimates for the number of neurons in the human brain range from 80 to 120 billion...
. It is between BA10
Brodmann area 10
Brodmann area 10, or BA10 is the frontopolar part of the frontal cortex in the human brain. BA10 was originally defined in terms of cytoarchitectonic traits in autopsy brains; modern functional imaging research cannot directly identify these boundaries and the terms anterior prefrontal, rostral...
and BA45
Brodmann area 45
Brodmann area 45 , is part of the frontal cortex in the human brain. Situated on the lateral surface, inferior to BA9 and adjacent to BA46.This area is also known as pars triangular ...
.
BA46 is known as middle frontal area 46. In the human brain it occupies approximately the middle third of the middle frontal gyrus
Middle frontal gyrus
The middle frontal gyrus makes up about one-third of the frontal lobe of the human brain....
and the most rostral portion of the inferior frontal gyrus
Inferior frontal gyrus
The inferior frontal gyrus is a gyrus of the frontal lobe . It is labelled gyrus frontalis inferior, its Latin name...
. Brodmann area 46 roughly corresponds with the dorsolateral prefrontal cortex
Dorsolateral prefrontal cortex
The dorsolateral prefrontal cortex , according to a more restricted definition, is roughly equivalent to Brodmann areas 9 and 46. According to a broader definition DL-PFC consists of the lateral portions of Brodmann areas 9 – 12, of areas 45, 46, and the superior part of area 47. These regions...
(DLPFC), although the borders of area 46 are based on cytoarchitecture rather than function. The DLPFC also encompasses part of granular frontal area 9, directly adjacent on the dorsal surface of the cortex.
Cytoarchitecturally, BA46 is bounded dorsally by the granular frontal area 9, rostroventrally by the frontopolar area 10 and caudally by the triangular area 45 (Brodmann-1909). There is some discrepancy between the extent of BA8
Brodmann area 8
Brodmann area 8 is one of Brodmann's cytologically defined regions of the brain. It is involved in planning complex movements.-Human:Brodmann area 8, or BA8, is part of the frontal cortex in the human brain...
(Brodmann-1905) and the same area as described by Walker (1940)
Function
The DLPFC plays a role in sustaining attentionAttention
Attention is the cognitive process of paying attention to one aspect of the environment while ignoring others. Attention is one of the most intensely studied topics within psychology and cognitive neuroscience....
and working memory
Working memory
Working memory has been defined as the system which actively holds information in the mind to do verbal and nonverbal tasks such as reasoning and comprehension, and to make it available for further information processing...
. Lesions to the DLPFC impair short-term memory and cause difficulty inhibiting responses. Lesions may also eliminate much of the ability to make judgements about what's relevant and what's not as well as causing problems in organization.
The DLPFC has recently been found to be involved in exhibiting self-control. http://sciencenow.sciencemag.org/cgi/content/full/2009/501/3
The dorsolateral prefrontal cortex is one of the few areas deactivated during REM sleep. Neuroscientist J. Allan Hobson has hypothesized that activation of the dorsolateral prefrontal cortex produce lucid dreams.
External links
- For Neuroanatomy of the area visit BrainInfo
See also
- Brodmann areaBrodmann areaA Brodmann area is a region of the cerebral cortex defined based on its cytoarchitectonics, or structure and organization of cells.-History:...
- List of regions in the human brain