The parahippocampal gyrus (or hippocampal gyrus) is a grey matter Grey matter is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil (dendrites and both unmyelinated axons and myelinated axons), glial cells (astroglia and oligodendrocytes) and capillaries. Grey matter contains neural cell bodies, in contrast to white matter, which does not and mostly contains myelinated cortical The cerebral cortex is a structure within the brain that plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It constitutes the outermost layer of the cerebrum. In preserved brains, it has a grey color, hence the name "grey matter". Grey matter is formed by neurons and their unmyelinated region of the brain The brain is the center of the nervous system in all vertebrate, and most invertebrate, animals. Some primitive animals such as jellyfish and starfish have a decentralized nervous system without a brain, while sponges lack any nervous system at all. In vertebrates, the brain is located in the head, protected by the skull and close to the primary that surrounds the hippocampus The hippocampus is a major component of the brains of humans and other mammals. It belongs to the limbic system and plays important roles in long-term memory and spatial navigation. Like the cerebral cortex, with which it is closely associated, it is a paired structure, with mirror-image halves in the left and right sides of the brain. In humans. This region plays an important role in memory In psychology, memory is an organism's mental ability to store, retain and recall information. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing the memory. The late nineteenth and early twentieth century put memory within the paradigms of cognitive psychology. In recent decades, it has encoding In the study of memory, encoding is the processing of physical sensory input into one's memory. It is considered the first of three steps in memory information processing; the remaining two steps are storage and retrieval. During memory encoding, information may be processed about space, time, and frequency through automatic processing or and retrieval. The anterior part of the gyrus includes the perirhinal Perirhinal cortex is a cortical region in the medial temporal lobe that is made up of Brodmann areas 35 and 36. In rats, it is located along and dorsal to the rhinal sulcus. It receives highly-processed sensory information from all sensory regions, and is generally accepted to be an important region for memory. It is bordered caudally by and entorhinal cortices. The term parahippocampal cortex is used to refer to an area that encompasses both the posterior portion of the parahippocampal gyrus and the medial portion of the fusiform gyrus The fusiform gyrus is part of the temporal lobe. It is also known as the occipitotemporal gyrus. Other sources have the fusiform gyrus above the occipitotemporal gyrus and underneath the parahippocampal gyrus.
The parahippocampal place area (PPA) is a subregion of the parahippocampal cortex that plays an important role in the encoding and recognition Recognition is a process that occurs in thinking when some event, process, pattern, or object recurs; a knowledge or feeling that someone or something present has been encountered before. Coming from the base cognition; cognition has various uses in different fields of study and has generally accepted to be used for the process of awareness or of scenes (rather than faces or objects). fMRI Functional MRI or functional Magnetic Resonance Imaging is a type of specialized MRI scan. It measures the haemodynamic response related to neural activity in the brain or spinal cord of humans or other animals. It is one of the most recently developed forms of neuroimaging. Since the early 1990s, fMRI has come to dominate the brain mapping field studies indicate that this region of the brain becomes highly active when human subjects view topographical scene stimuli such as images of landscapes, cityscapes, or rooms (i.e. images of "places"). The region was first described by Russell Epstein (currently at the University of Pennsylvania) and Nancy Kanwisher (currently at MIT) in 1998 ([1], see also other similar reports by Geoffrey Aguirre [2]
[3] and Alumit Ishai [4]). Damage to the PPA (for example, due to stroke) often leads to a syndrome in which patients cannot visually recognize scenes even though they can recognize the individual objects in the scenes (such as people, furniture, etc.). The PPA is often considered the complement of the fusiform face area (FFA), a nearby cortical region that responds strongly whenever faces are viewed, and which is believed to be important for face recognition.
Additional research has increased the probability that the right parahippocampal gyrus in particular has functions beyond the contextualizing of visual background. Tests by a California-based group led by Katherine P. Rankin indicate that the lobe may play a crucial role in identifying social context as well, including paralinguistic elements of verbal communication[1]
Additional images
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Coronal section
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Human brainstem anterior view
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Human brain inferior-medial view
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References
- ^ NY Times
| Brain The brain is the center of the nervous system in all vertebrate, and most invertebrate, animals. Some primitive animals such as jellyfish and starfish have a decentralized nervous system without a brain, while sponges lack any nervous system at all. In vertebrates, the brain is located in the head, protected by the skull and close to the primary: telencephalon (cerebrum The cerebrum or telencephalon, together with the diencephalon, constitute the forebrain. It is the most anterior or, especially in humans, most superior region of the vertebrate central nervous system. "Telencephalon" refers to the embryonic structure, from which the mature "cerebrum" develops. The dorsal telencephalon, or · cerebral cortex The cerebral cortex is a structure within the brain that plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It constitutes the outermost layer of the cerebrum. In preserved brains, it has a grey color, hence the name "grey matter". Grey matter is formed by neurons and their unmyelinated · cerebral hemispheres) |
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Frontal lobe The frontal lobe is an area in the brain of mammals. It is located at the front of each cerebral hemisphere and positioned anterior to the parietal lobes and above and anterior to the temporal lobes. It is separated from the parietal lobe by the primary motor cortex, which controls voluntary movements of specific body parts associated with the
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Precentral gyrus The primary motor cortex is a brain region that in humans is located in the posterior portion of the frontal lobe. It works in association with pre-motor areas to plan and execute movements. M1 contains large neurons known as Betz cells which send long axons down the spinal cord to synapse onto alpha motor neurons which connect to the muscles. Pre- (Primary motor cortex The primary motor cortex is a brain region that in humans is located in the posterior portion of the frontal lobe. It works in association with pre-motor areas to plan and execute movements. M1 contains large neurons known as Betz cells which send long axons down the spinal cord to synapse onto alpha motor neurons which connect to the muscles. Pre-, 4 Brodmann area 4 comprises the primary motor cortex of the human brain. It is located in the posterior portion of the frontal lobe)
Superior frontal gyrus The superior frontal gyrus makes up about one-third of the frontal lobe of the human brain. It is bounded laterally by the superior frontal sulcus/Frontal eye fields The frontal eye fields is a region located in the premotor cortex, which is part of the frontal cortex of the primate brain (6 Brodmann area 6, or BA6, is part of the frontal cortex in the human brain. Situated just anterior to the primary motor cortex , it is composed of the premotor cortex and medially the supplementary motor area, or SMA. This large area of the frontal cortex is believed to play a role in the planning of complex, coordinated movements, 8 Brodmann area 8 is one of Brodmann's cytologically defined regions of the brain. It is involved in planning complex movements, 9 Brodmann area 9, or BA9, is part of the frontal cortex in the human brain. It contributes to the dorsolateral prefrontal cortex) · Middle frontal gyrus (46 Brodmann area 46, or BA46, is part of the frontal cortex in the human brain. It is located inbetween BA10 and BA45) · Inferior frontal gyrus The inferior frontal gyrus is a gyrus of the frontal lobe of the human brain. Its superior border is the inferior frontal sulcus, its inferior border the lateral fissure, and its posterior border is the inferior precentral sulcus. Above it is the middle frontal gyrus, behind it the precentral gyrus/Broca's area The importance of Broca’s area in producing language has been recognized since Paul Pierre Broca reported impairments in two patients he encountered. They had lost the ability to speak after injury to the posterior inferior frontal gyrus of the brain. Since then, the approximate region he identified has become known as Broca’s area, and the (44 Brodmann area 44, or BA44, is part of the frontal cortex in the human brain. Situated just anterior to premotor cortex and on the lateral surface, inferior to BA9-Pars opercularis In the human brain the Pars opercularis is the part of the inferior frontal gyrus that lies between the inferior precentral sulcus and the ascending ramus of the lateral sulcus. It is called opercularis because it covers part of the insula. The pars opercularis together with the pars triangularis form Broca's 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-Pars triangularis Pars triangularis is a region of Broca's area in the left inferior frontal gyrus (IFG) of the frontal lobe in the human brain mapping to Brodmann area 45. The inferior frontal sulcus forms the superior boundary, the anterior horizontal ramus provides its inferior boundary, and the caudal boundary is made by the anterior ascending ramus. The pt)
Orbitofrontal cortex The orbitofrontal cortex is a region of association cortex of the human brain involved in cognitive processes such as decision-making. The name of this region is based upon the region's location within the frontal lobes, resting above the orbits of the eyes. It is defined as the part of the prefrontal cortex that receives projections from the (10 Brodmann area 10, or BA10, is part of the frontal cortex in the human brain. BA10 encompasses the most anterior part of the frontal cortex, known as the frontopolar region. This area is believed to play a part in strategic processes involved in memory retrieval and executive function, 11 Brodmann area 11 is one of Brodmann's cytologically defined regions of the brain. It is involved in planning, reasoning, and decision making, 12 Superior frontal gyrus/Frontal eye fields · Middle frontal gyrus (46) · Inferior frontal gyrus/Broca's area (44-Pars opercularis, 45-Pars triangularis), 47 Brodmann area 47, or BA47, is part of the frontal cortex in the human brain. Curving from the lateral surface of the frontal lobe into the ventral frontal cortex. It is below areas BA10 and BA45, and beside BA11)
Prefrontal cortex The prefrontal cortex is the anterior part of the frontal lobes of the brain, lying in front of the motor and premotor areas · Premotor cortex The premotor cortex is an area of motor cortex lying within the frontal lobe of the brain. It extends 3 mm anterior to the primary motor cortex, near the Sylvian fissure, before narrowing to approximately 1 mm near the medial longitudinal fissure, which serves as the posterior border for the prefrontal cortex. The premotor cortex is largely
Precentral sulcus The precentral sulcus lies parallel to, and in front of, the central sulcus · Superior frontal sulcus The superior frontal sulcus is a sulcus between the superior frontal gyrus and the middle frontal gyrus · Inferior frontal sulcus The inferior frontal sulcus is a sulcus between the middle frontal gyrus and the inferior frontal gyrus · Olfactory sulcus This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated
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Parietal lobe The parietal lobe is a lobe in the brain. It is positioned above (superior to) the occipital lobe and behind (posterior to) the frontal lobe
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Somatosensory cortex (Primary The lateral postcentral gyrus is a prominent structure in the parietal lobe of the human brain and an important landmark. It was initially defined from surface stimulation studies of Penfield, and parallel surface potential studies of Bard, Woolsey, and Marshall. Although initially defined to be roughly the same as Brodmann areas 3, 1 and 2, more (1 · 2 · 3 · 43 In the human subcentral area 43 is a subdivision of the cytoarchitecturally defined postcentral region of cerebral cortex. It occupies the postcentral gyrus and the precentral gyrus between the ventrolateral extreme of the central sulcus and the depth of the lateral sulcus at the insula. Its rostral and caudal borders are approximated by the) · Secondary Brodmann area 5 is part of the parietal cortex in the human brain. It is situated immediately posterior to the primary somatosensory areas , and anterior to Brodmann area 7 (5 Brodmann area 5 is part of the parietal cortex in the human brain. It is situated immediately posterior to the primary somatosensory areas , and anterior to Brodmann area 7)) · Precuneus The precuneus is a structure in the brain positioned above the cuneus and located in the parietal lobe. According to some authors[who?], the precuneus is part of the limbic system. It is believed that it contains a sensory-based map of one's own body (7m Brodmann area 7 is part of the parietal cortex in the human brain. Situated posterior to the primary somatosensory cortex , and superior to visual cortices (Brodmann areas 17, 18 and 19), this region is believed to play in visuo-motor coordination (e.g., in reaching to grasp an object)) · Parietal operculum The parietal operculum, forming the superior bank of the sylvian fissure, as studied in the cat, contains the secondary somatosensory representation, 'S-II', and a second somatotopic representation . Anatomically, primate S-II receives inputs from area 3 and area 1, and projects to PV and area 7. PV has projections to area 5 and premotor areas
Parietal lobules (Superior The superior parietal lobule is bounded in front by the upper part of the postcentral sulcus, but is usually connected with the posterior central gyrus above the end of the sulcus (7l Brodmann area 7 is part of the parietal cortex in the human brain. Situated posterior to the primary somatosensory cortex , and superior to visual cortices (Brodmann areas 17, 18 and 19), this region is believed to play in visuo-motor coordination (e.g., in reaching to grasp an object)) · Inferior (40)) · Angular gyrus (39)
Intraparietal sulcus · Marginal sulcus
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Occipital lobe
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Primary visual cortex (17) · (Cuneus · Lingual gyrus · Lateral occipital gyrus (18, 19))
Calcarine fissure
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Temporal lobe
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Primary auditory cortex (41, 42) · Superior temporal gyrus (38, 22/Wernicke's area) · Middle temporal gyrus (21) · Inferior temporal gyrus (20)
Fusiform gyrus (37) Medial temporal lobe (Amygdala · Parahippocampal gyrus (27 · 28 · 34 · 35 · 36))
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Interlobar sulci/fissures
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lateral: Central (frontal+parietal) · Lateral (frontal+parietal+temporal) · Parietoöccipital
medial: Medial longitudinal · Cingulate (frontal+cingulate) · Collateral (temporal+occipital)
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| Cingulate cortex/gyrus |
Subgenual area (25) · Anterior cingulate (24, 32, 33) · Posterior cingulate (23, 31) · Retrosplenial cortex (26, 29, 30)
Callosal sulcus
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| White matter tracts |
Commissural fibers · Association fibers
Internal capsule (Anterior limb · Genu · Posterior limb) · Corona radiata · External capsule · Lamina terminalis · Extreme capsule · Semioval center
Olfactory tract · Terminal stria · Diagonal band of Broca
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| Other |
Insular cortex
gray: Olfactory bulb · Anterior olfactory nucleus · Basal optic nucleus of Meynert · Substantia innominata · Anterior perforated substance
Corpus striatum · Limbic lobe
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| Some categorizations are approximations, and some Brodmann areas span gyri. |
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Categories: Cerebrum | Neuroanatomy |
