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Subthalamus
The subthalamus or prethalamus is a part of the diencephalon. Its most prominent structure is the subthalamic nucleus. The subthalamus connects to the globus pallidus, a basal nucleus of the telencephalon. Structure The subthalamus is located ventral to the thalamus, medial to the internal capsule and lateral to the hypothalamus. It is a region formed by several grey matter nuclei and their associated white matter structures, namely: *The subthalamic nucleus, whose neurons contain glutamate and have excitatory effects over neurons of globus pallidus and substantia nigra *Zona incerta, located between fields of Forel H1 and H2. It is continuous with the thalamic reticular nucleus and receives input from the precentral cortex. *Subthalamic fasciculus, formed by fibers that connect the globus pallidus with the subthalamic nucleus * Fields of Forel *Ansa lenticularis During development the subthalamus is continuous with the hypothalamus, but is separated by white mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fields Of Forel
The fields of Forel are areas in a deep part of the brain known as the diencephalon. They are below the thalamus and consist of three defined, white matter areas of the subthalamus. These three regions are also named "H fields": *Field H1, is the thalamic fasciculus, a horizontal white matter tract composed of the ansa lenticularis, lenticular fasciculus, and cerebellothalamic tracts between the subthalamus and the thalamus. These fibers are projections to the ventral anterior and ventral lateral thalamus from the basal ganglia (globus pallidus) and the cerebellum. H1 is separated from H2 by the zona incerta. *Field H2 (synonymous with lenticular fasciculus) is also made up of projections from the pallidum to the thalamus, but these course the subthalamic nucleus (dorsal). *Field H (sometimes called field H3) is a large zone of mixed grey and white matter from the pallidothalamic tracts of the lenticular fasciculus and the ansa lenticularis which combine in an area just in fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diencephalon
The diencephalon (or interbrain) is a division of the forebrain (embryonic ''prosencephalon''). It is situated between the telencephalon and the midbrain The midbrain or mesencephalon is the forward-most portion of the brainstem and is associated with vision, hearing, motor control, sleep and wakefulness, arousal ( alertness), and temperature regulation. The name comes from the Greek ''mesos'', " ... (embryonic ''mesencephalon''). The diencephalon has also been known as the 'tweenbrain in older literature. It consists of structures that are on either side of the third ventricle, including the thalamus, the hypothalamus, the epithalamus and the subthalamus. The diencephalon is one of the main vesicles of the brain formed during embryogenesis. During the third week of development a neural tube is created from the ectoderm, one of the three primary germ layers. The tube forms three main vesicles during the third week of development: the prosencephalon, the mesencepha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subthalamic Nucleus
The subthalamic nucleus (STN) is a small lens-shaped nucleus in the brain where it is, from a functional point of view, part of the basal ganglia system. In terms of anatomy, it is the major part of the subthalamus. As suggested by its name, the subthalamic nucleus is located ventral to the thalamus. It is also dorsal to the substantia nigra and medial to the internal capsule. It was first described by Jules Bernard Luys in 1865, and the term ''corpus Luysi'' or ''Luys' body'' is still sometimes used. Anatomy Structure The principal type of neuron found in the subthalamic nucleus has rather long, sparsely spiny dendrites. In the more centrally located neurons, the dendritic arbors have a more ellipsoidal shape. The dimensions of these arbors (1200 μm, 600 μm, and 300 μm) are similar across many species—including rat, cat, monkey and human—which is unusual. However, the number of neurons increases with brain size as well as the external dimensions o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Globus Pallidus
The globus pallidus (GP), also known as paleostriatum or dorsal pallidum, is a subcortical structure of the brain. It consists of two adjacent segments, one external, known in rodents simply as the globus pallidus, and one internal, known in rodents as the entopeduncular nucleus. It is part of the telencephalon, but retains close functional ties with the subthalamus in the diencephalon – both of which are part of the extrapyramidal motor system. The globus pallidus is a major component of the basal ganglia, with principal inputs from the striatum, and principal direct outputs to the thalamus and the substantia nigra. The latter is made up of similar neuronal elements, has similar afferents from the striatum, similar projections to the thalamus, and has a similar synaptology. Neither receives direct cortical afferents, and both receive substantial additional inputs from the intralaminar thalamus. Globus pallidus is Latin for "pale globe". Structure Pallidal nuclei are made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subthalamic Nucleus
The subthalamic nucleus (STN) is a small lens-shaped nucleus in the brain where it is, from a functional point of view, part of the basal ganglia system. In terms of anatomy, it is the major part of the subthalamus. As suggested by its name, the subthalamic nucleus is located ventral to the thalamus. It is also dorsal to the substantia nigra and medial to the internal capsule. It was first described by Jules Bernard Luys in 1865, and the term ''corpus Luysi'' or ''Luys' body'' is still sometimes used. Anatomy Structure The principal type of neuron found in the subthalamic nucleus has rather long, sparsely spiny dendrites. In the more centrally located neurons, the dendritic arbors have a more ellipsoidal shape. The dimensions of these arbors (1200 μm, 600 μm, and 300 μm) are similar across many species—including rat, cat, monkey and human—which is unusual. However, the number of neurons increases with brain size as well as the external dimensions o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zona Incerta
The zona incerta (ZI) is a horizontally elongated region of gray matter in the subthalamus below the thalamus. Its connections project extensively over the brain from the cerebral cortex down into the spinal cord. Its function is unknown, though several potential functions related to "limbic–motor integration" have been proposed, such as controlling visceral activity and pain; gating sensory input and synchronizing cortical and subcortical brain rhythms. Its dysfunction may play a role in central pain syndrome. It has also been identified as a promising deep brain stimulation therapy target for treating Parkinson's disease. Its existence was first described by Auguste Forel in 1877 as a "region of which nothing certain can be said". A hundred and thirty years later in 2007, Nadia Urbain and Martin Deschênes of Université Laval noted that the "zona incerta is among the least studied regions of the brain; its name does not even appear in the index of many textbooks." Str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ansa Lenticularis
The ansa lenticularis (''ansa lentiformis'' in older texts) is a part of the brain, making up the superior layer of the substantia innominata. Its fibers, derived from the medullary lamina of the lentiform nucleus, pass medially to end in the thalamus and subthalamic region, while others are said to end in the tegmentum and red nucleus. It is classified by NeuroNames as part of the subthalamus The subthalamus or prethalamus is a part of the diencephalon. Its most prominent structure is the subthalamic nucleus. The subthalamus connects to the globus pallidus, a basal nucleus of the telencephalon. Structure The subthalamus is locate .... References External links * {{Authority control Thalamic connections Basal ganglia connections ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subthalamic Fasciculus
The subthalamic fasciculus is a bi-directional neural tract that connects the subthalamic nucleus and the globus pallidus The globus pallidus (GP), also known as paleostriatum or dorsal pallidum, is a subcortical structure of the brain. It consists of two adjacent segments, one external, known in rodents simply as the globus pallidus, and one internal, known in rode .... References External links * http://isc.temple.edu/neuroanatomy/lab/atlas/dan1/ * https://web.archive.org/web/20071126015854/http://www.sci.uidaho.edu/med532/subthalamus.htm Basal ganglia connections Subthalamus {{Neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal Ganglia
The basal ganglia (BG), or basal nuclei, are a group of subcortical nuclei, of varied origin, in the brains of vertebrates. In humans, and some primates, there are some differences, mainly in the division of the globus pallidus into an external and internal region, and in the division of the striatum. The basal ganglia are situated at the base of the forebrain and top of the midbrain. Basal ganglia are strongly interconnected with the cerebral cortex, thalamus, and brainstem, as well as several other brain areas. The basal ganglia are associated with a variety of functions, including control of voluntary motor movements, procedural learning, habit learning, conditional learning, eye movements, cognition, and emotion. The main components of the basal ganglia – as defined functionally – are the striatum, consisting of both the dorsal striatum ( caudate nucleus and putamen) and the ventral striatum ( nucleus accumbens and olfactory tubercle), the globus pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grey Matter
Grey matter is a major component of the central nervous system, consisting of neuronal Soma (biology), cell bodies, neuropil (dendrites and unmyelinated axons), Glia, glial cells (astrocytes and oligodendrocytes), synapses, and Capillary, capillaries. Grey matter is distinguished from white matter in that it contains numerous cell bodies and relatively few myelinated axons, while white matter contains relatively few cell bodies and is composed chiefly of long-range myelinated axons. The colour difference arises mainly from the whiteness of myelin. In living tissue, grey matter actually has a very light grey colour with yellowish or pinkish hues, which come from capillary blood vessels and neuronal cell bodies. Structure Grey matter refers to unmyelinated neurons and other cells of the central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
