Parahippocampal gyrus
Human brainstem anterior view (Gyrus parahippocampalis is #7, near center right.)
Parahippocampal gyrus labeled at bottom center.
Latin	gyrus parahippocampalis
MeSH	Parahippocampal+Gyrus

The parahippocampal gyrus is a grey matter cortical region of the brain that surrounds the hippocampus. This region plays an important role in memory encoding and retrieval.

It has been involved in some cases of hippocampal sclerosis.^[1]

Asymmetry has been observed in schizophrenia.^[2]

Contents 1 Divisions 2 Function 2.1 Scene recognition 2.2 Social context 3 Additional images 4 References 5 External links

[edit] Divisions

The anterior part of the gyrus includes the perirhinal and entorhinal cortices^{[citation needed]}.

The term parahippocampal cortex is used to refer to an area that encompasses both the posterior parahippocampal gyrus and the medial portion of the fusiform gyrus.

[edit] Function

[edit] Scene recognition

The parahippocampal place area (PPA) is a subregion of the parahippocampal cortex that plays an important role in the encoding and recognition of scenes (rather than faces or objects). fMRI 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,^[3] see also other similar reports by Geoffrey Aguirre^[4][5] and Alumit Ishai.^[6]

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.

[edit] Social context

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.^[7]

[edit] Additional images

Coronal section

Human brain inferior-medial view

Basal view of a human brain

[edit] References

[edit] External links

• NeuroNames hier-146
• http://www2.umdnj.edu/~neuro/studyaid/Practical2000/Q35.htm
• Temporal-lobe.com An interactive diagram of the rat parahippocampal-hippocampal region

v • d • e Human brain: forebrain (cerebrum · cerebral cortex · cerebral hemispheres, grey matter) (TA A14.1.09.002-240, 301-320, GA 9.818-826) Frontal lobe Superolateral Prefrontal Superior frontal gyrus (4l, 6l, 8l) · Middle frontal gyrus (9l, 10l, 46) Inferior frontal gyrus: 11l · 47-Pars orbitalis · Broca's area (44-Pars opercularis, 45-Pars triangularis) Superior frontal sulcus · Inferior frontal sulcus Precentral Precentral gyrus · Precentral sulcus Medial/inferior Prefrontal Superior frontal gyrus (4m, 6m) · Medial frontal gyrus (8m, 9m) Paraterminal gyrus/Paraolfactory area (12) · Straight gyrus (11m) · Orbital gyri/Orbitofrontal cortex (10m, 11m, 12) · Ventromedial prefrontal cortex (10m) · Subcallosal area (25) Olfactory sulcus · Orbital sulci Precentral Paracentral lobule (4) · Paracentral sulcus Both Primary motor cortex (4) · Premotor cortex (6) · Supplementary motor area (6) · Frontal eye fields (8) Parietal lobe Superolateral Superior parietal lobule (5l, 7l) · Inferior parietal lobule (40-Supramarginal gyrus, 39-Angular gyrus) · Parietal operculum (43) Intraparietal sulcus Medial/inferior Paracentral lobule (1m, 2m, 3m, 5m) · Precuneus (7m) Marginal sulcus Both Postcentral gyrus/primary somatosensory cortex (1 · 2 · 3) · Secondary somatosensory cortex (5) · Posterior parietal cortex (7) Occipital lobe Superolateral Occipital pole of cerebrum · Lateral occipital gyrus (18, 19) · Lunate sulcus · Transverse occipital sulcus Medial/inferior Primary visual cortex (17) · Cuneus · Lingual gyrus Calcarine fissure Temporal lobe Superolateral Transverse temporal gyrus/Primary auditory cortex (41, 42) · Superior temporal gyrus (38, 22/Wernicke's area) · Middle temporal gyrus (21) · Inferior temporal gyrus (20) Superior temporal sulcus · Inferior temporal sulcus Medial/inferior Fusiform gyrus (37) Medial temporal lobe ((27 · 28 · 34 · 35 · 36)) Inferior temporal sulcus Interlobar sulci/fissures Superolateral Central (frontal+parietal) · Lateral (frontal+parietal+temporal) · Parieto-occipital · Preoccipital notch Medial/inferior Medial longitudinal · Cingulate (frontal+cingulate) · Collateral (temporal+occipital) · Callosal sulcus Limbic lobe Parahippocampal gyrus anterior (Entorhinal cortex, Perirhinal cortex) · Posterior parahippocampal gyrus · Prepyriform area Cingulate cortex/gyrus Subgenual area (25) · Anterior cingulate (24, 32, 33) · Posterior cingulate (23, 31) Isthmus of cingulate gyrus: Retrosplenial cortex (26, 29, 30) Hippocampal formation Hippocampal sulcus · Fimbria of hippocampus · Dentate gyrus Other Supracallosal gyrus · Uncus Insular lobe Long gyrus of insula · Short gyri of insula · Circular sulcus of insula General Operculum · Poles of cerebral hemispheres Some categorizations are approximations, and some Brodmann areas span gyri.

v • d • e Papez circuit pathway Diencephalon Mammillary body → Mammillothalamic tract → Anterior nuclei of thalamus → Telencephalon Anterior limb of internal capsule → Cingulate gyrus → Cingulum → Parahippocampal gyrus → Entorhinal cortex → Perforant path → Hippocampus/Hippocampal formation (CA3 → CA1 → Subiculum) → Fornix →

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