Indusium griseum

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Indusium griseum
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Scheme of rhinencephalon. (Indusium griseum labelled as gyrus supracallosus at center top.)
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Corpus callosum from above.
Identifiers
NeuroNames 173
NeuroLex ID birnlex_1316
TA98 A14.1.09.246
TA2 5526
FMA 62488
Anatomical terms of neuroanatomy

The indusium griseum, (supracallosal gyrus, gyrus epicallosus, dorsal hippocampal continuation) [1] consists of a thin membranous layer of grey matter in contact with the upper surface of the corpus callosum and continuous laterally with the grey matter of the cingulate cortex and inferiorly with the hippocampus. It is vestigial in humans and is a remnant of the former position of the hippocampus in lower animals.

On either side of the midline of the indusium griseum are two ridges formed by bands of longitudinally directed fibers known as the medial and lateral longitudinal striae. [2]

The indusium griseum is prolonged around the splenium of the corpus callosum as a delicate layer, the fasciolar gyrus, [3] which is continuous below with the surface of the dentate gyrus. [4] The indusium griseum and fasciolar gyrus are very small components of the limbic lobe, and are continuations of the hippocampal formation, forming an unremarkable thin continuous ring of grey matter at the edge of the cortex. [4]

Toward the genu of the corpus callosum it curves down along the rostrum to form the subcallosal gyrus. [5]

Related Research Articles

<span class="mw-page-title-main">Entorhinal cortex</span> Area of the temporal lobe of the brain

The entorhinal cortex (EC) is an area of the brain's allocortex, located in the medial temporal lobe, whose functions include being a widespread network hub for memory, navigation, and the perception of time. The EC is the main interface between the hippocampus and neocortex. The EC-hippocampus system plays an important role in declarative (autobiographical/episodic/semantic) memories and in particular spatial memories including memory formation, memory consolidation, and memory optimization in sleep. The EC is also responsible for the pre-processing (familiarity) of the input signals in the reflex nictitating membrane response of classical trace conditioning; the association of impulses from the eye and the ear occurs in the entorhinal cortex.

<span class="mw-page-title-main">Corpus callosum</span> White matter tract connecting the two cerebral hemispheres

The corpus callosum, also callosal commissure, is a wide, thick nerve tract, consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain. The corpus callosum is only found in placental mammals. It spans part of the longitudinal fissure, connecting the left and right cerebral hemispheres, enabling communication between them. It is the largest white matter structure in the human brain, about 10 cm (3.9 in) in length and consisting of 200–300 million axonal projections.

<span class="mw-page-title-main">Dentate gyrus</span> Region of the hippocampus in the brain

The dentate gyrus (DG) is part of the hippocampal formation in the temporal lobe of the brain, which also includes the hippocampus and the subiculum. The dentate gyrus is part of the hippocampal trisynaptic circuit and is thought to contribute to the formation of new episodic memories, the spontaneous exploration of novel environments and other functions. The dentate gyrus has toothlike projections from which it is named.

<span class="mw-page-title-main">Cerebral hemisphere</span> Left and right cerebral hemispheres of the brain

The vertebrate cerebrum (brain) is formed by two cerebral hemispheres that are separated by a groove, the longitudinal fissure. The brain can thus be described as being divided into left and right cerebral hemispheres. Each of these hemispheres has an outer layer of grey matter, the cerebral cortex, that is supported by an inner layer of white matter. In eutherian (placental) mammals, the hemispheres are linked by the corpus callosum, a very large bundle of nerve fibers. Smaller commissures, including the anterior commissure, the posterior commissure and the fornix, also join the hemispheres and these are also present in other vertebrates. These commissures transfer information between the two hemispheres to coordinate localized functions.

<span class="mw-page-title-main">Cingulate cortex</span> Part of the limbic lobe of the brain cortex

The cingulate cortex is a part of the brain situated in the medial aspect of the cerebral cortex. The cingulate cortex includes the entire cingulate gyrus, which lies immediately above the corpus callosum, and the continuation of this in the cingulate sulcus. The cingulate cortex is usually considered part of the limbic lobe.

<span class="mw-page-title-main">Cerebrum</span> Large part of the brain containing the cerebral cortex

The cerebrum, telencephalon or endbrain is the largest part of the brain, containing the cerebral cortex as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb. In the human brain, the cerebrum is the uppermost region of the central nervous system. The cerebrum develops prenatally from the forebrain (prosencephalon). In mammals, the dorsal telencephalon, or pallium, develops into the cerebral cortex, and the ventral telencephalon, or subpallium, becomes the basal ganglia. The cerebrum is also divided into approximately symmetric left and right cerebral hemispheres.

<span class="mw-page-title-main">Fornix (neuroanatomy)</span> Bundle of nerve fibers in the brain

The fornix is a C-shaped bundle of nerve fibers in the brain that acts as the major output tract of the hippocampus. The fornix also carries some afferent fibers to the hippocampus from structures in the diencephalon and basal forebrain. The fornix is part of the limbic system. While its exact function and importance in the physiology of the brain are still not entirely clear, it has been demonstrated in humans that surgical transection—the cutting of the fornix along its body—can cause memory loss. There is some debate over what type of memory is affected by this damage, but it has been found to most closely correlate with recall memory rather than recognition memory. This means that damage to the fornix can cause difficulty in recalling long-term information such as details of past events, but it has little effect on the ability to recognize objects or familiar situations.

<span class="mw-page-title-main">Neural pathway</span> Connection formed between neurons that allows neurotransmission

In neuroanatomy, a neural pathway is the connection formed by axons that project from neurons to make synapses onto neurons in another location, to enable neurotransmission. Neurons are connected by a single axon, or by a bundle of axons known as a nerve tract, or fasciculus. Shorter neural pathways are found within grey matter in the brain, whereas longer projections, made up of myelinated axons, constitute white matter.

<span class="mw-page-title-main">Longitudinal fissure</span> Deep groove separating the two cerebral hemispheres of the vertebrate brain

The longitudinal fissure is the deep groove that separates the two cerebral hemispheres of the vertebrate brain. Lying within it is a continuation of the dura mater called the falx cerebri. The inner surfaces of the two hemispheres are convoluted by gyri and sulci just as is the outer surface of the brain.

<span class="mw-page-title-main">Lateral ventricles</span> Two largest ventricles in each cerebral hemisphere

The lateral ventricles are the two largest ventricles of the brain and contain cerebrospinal fluid. Each cerebral hemisphere contains a lateral ventricle, known as the left or right lateral ventricle, respectively.

<span class="mw-page-title-main">Cingulum (brain)</span> Nerve tract from the cingulate gyrus to the entorhinal cortex in the brain

In neuroanatomy, the cingulum or cingulum bundle is an association tract, a nerve tract that projects from the cingulate gyrus to the entorhinal cortex in the brain, allowing for communication between components of the limbic system. It forms the white matter core of the cingulate gyrus, following it from the subcallosal gyrus of the frontal lobe beneath the rostrum of corpus callosum to the parahippocampal gyrus and uncus of the temporal lobe.

<span class="mw-page-title-main">Lobes of the brain</span> Parts of the cerebrum

The lobes of the brain are the four major identifiable regions of the human cerebral cortex, and they comprise the surface of each hemisphere of the cerebrum. The two hemispheres are roughly symmetrical in structure, and are connected by the corpus callosum. Some sources include the insula and limbic lobe but the limbic lobe incorporates parts of the other lobes. The lobes are large areas that are anatomically distinguishable, and are also functionally distinct. Each lobe of the brain has numerous ridges, or gyri, and furrows, sulci that constitute further subzones of the cortex. The expression "lobes of the brain" usually refers only to those of the cerebrum, not to the distinct areas of the cerebellum.

<span class="mw-page-title-main">Posterior cerebral artery</span> Artery which supplies blood to the occipital lobe of the brain

The posterior cerebral artery (PCA) is one of a pair of cerebral arteries that supply oxygenated blood to the occipital lobe, as well as the medial and inferior aspects of the temporal lobe of the human brain. The two arteries originate from the distal end of the basilar artery, where it bifurcates into the left and right posterior cerebral arteries. These anastomose with the middle cerebral arteries and internal carotid arteries via the posterior communicating arteries.

<span class="mw-page-title-main">Perforant path</span>

In the brain, the perforant path or perforant pathway provides a connectional route from the entorhinal cortex to all fields of the hippocampal formation, including the dentate gyrus, all CA fields, and the subiculum.

<span class="mw-page-title-main">Subcallosal gyrus</span>

The subcallosal gyrus is a narrow lamina on the medial surface of the hemisphere in front of the lamina terminalis, behind the parolfactory area, and below the rostrum of the corpus callosum. It is continuous around the genu of the corpus callosum with the indusium griseum. It's also considered a part of limbic system of the brain.

The trisynaptic circuit or trisynaptic loop is a relay of synaptic transmission in the hippocampus. The trisynaptic circuit is a neural circuit in the hippocampus, which is made up of three major cell groups: granule cells in the dentate gyrus, pyramidal neurons in CA3, and pyramidal neurons in CA1. The hippocampal relay involves 3 main regions within the hippocampus which are classified according to their cell type and projection fibers. The first projection of the hippocampus occurs between the entorhinal cortex (EC) and the dentate gyrus (DG). The entorhinal cortex transmits its signals from the parahippocampal gyrus to the dentate gyrus via granule cell fibers known collectively as the perforant path. The dentate gyrus then synapses on pyramidal cells in CA3 via mossy cell fibers. CA3 then fires to CA1 via Schaffer collaterals which synapse in the subiculum and are carried out through the fornix. Collectively the dentate gyrus, CA1 and CA3 of the hippocampus compose the trisynaptic loop.

<span class="mw-page-title-main">Hippocampus anatomy</span> Component of brain anatomy

Hippocampus anatomy describes the physical aspects and properties of the hippocampus, a neural structure in the medial temporal lobe of the brain. It has a distinctive, curved shape that has been likened to the sea-horse monster of Greek mythology and the ram's horns of Amun in Egyptian mythology. This general layout holds across the full range of mammalian species, from hedgehog to human, although the details vary. For example, in the rat, the two hippocampi look similar to a pair of bananas, joined at the stems. In the human and other primates, the portion of the hippocampus near the base of the temporal lobe is much broader than the part at the top. Due to the three-dimensional curvature of this structure, two-dimensional sections such as shown are commonly seen. Neuroimaging pictures can show a number of different shapes, depending on the angle and location of the cut.

In human neuroanatomy, the longitudinal striae are two bundles of fibres embedded in the indusium griseum running along the corpus callosum of the brain. They were originally described by Italian physician, epidemiologist and anatomist Giovanni Maria Lancisi. The striae are categorized as medial longitudinal stria and lateral longitudinal stria; the area between the striae is a useful neurosurgical mark of the middle of the corpus callosum.

<span class="mw-page-title-main">Hippocampal subfields</span> Part of the brain of mammals

The hippocampal subfields are four subfields CA1, CA2, CA3, and CA4 that make up the structure of the hippocampus. Regions described in the hippocampus are the head, body, and tail, and other hippocampal subfields include the dentate gyrus, the presubiculum, and the subiculum. The CA subfields use the initials of cornu ammonis, an earlier name of the hippocampus.

References

PD-icon.svgThis article incorporates text in the public domain from page 827 of the 20th edition of Gray's Anatomy (1918)

  1. Cleland, Thomas A.; Linster, Christiane; Haberland, G. (2019). "Central olfactory structures". Handbook of Clinical Neurology. 164: 79–96. doi:10.1016/B978-0-444-63855-7.00006-X.
  2. Di Ieva, A; Fathalla, H; Cusimano, MD; Tschabitscher, M (January 2015). "The indusium griseum and the longitudinal striae of the corpus callosum". Cortex. 62: 34–40. doi:10.1016/j.cortex.2014.06.016. PMID   25091482. S2CID   1246791.
  3. "fasciola gyrus". TheFreeDictionary.com.
  4. 1 2 Kiernan, JA (2012). "Anatomy of the temporal lobe". Epilepsy Research and Treatment. 2012: 176157. doi: 10.1155/2012/176157 . PMC   3420617 . PMID   22934160.
  5. Naidich, Thomas P.; Castillo, Mauricio; Cha, Soonmee; Smirniotopoulos, James G. (31 October 2012). Imaging of the Brain, Expert Radiology Series,1: Imaging of the Brain. Elsevier Health Sciences. ISBN   978-1416050094.