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Magnocellular Red Nucleus
The magnocellular red nucleus (mRN or mNR or RNm) is located in the rostral midbrain and is involved in motor coordination. Together with the parvocellular red nucleus, the mRN makes up the red nucleus. Due to the role it plays in motor coordination, the magnocellular red nucleus may be implicated in the characteristic symptom of restless legs syndrome (RLS). The mRN receives most of its signals from the motor cortex and the cerebellum. Overview The red nucleus (RN), a group of neurons composed of the parvocellular red nucleus (pRN) and the magnocellular red nucleus (mRN), contributes to movement and motor control within the forelimb. Primate studies have shown that more forelimb mRN neuron discharges are observed when the location of the target object a primate is reaching is on the right or above. This demonstrates that although forelimb mRN neurons are involved in grasping movements to the left, right, above, and below, they play a greater role when an organism is attemptin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midbrain
The midbrain or mesencephalon is the uppermost portion of the brainstem connecting the diencephalon and cerebrum with the pons. It consists of the cerebral peduncles, tegmentum, and tectum. It is functionally associated with vision, hearing, motor control, sleep and wakefulness, arousal (alertness), and temperature regulation.Breedlove, Watson, & Rosenzweig. Biological Psychology, 6th Edition, 2010, pp. 45-46 The name ''mesencephalon'' comes from the Greek ''mesos'', "middle", and ''enkephalos'', "brain". Structure The midbrain is the shortest segment of the brainstem, measuring less than 2cm in length. It is situated mostly in the posterior cranial fossa, with its superior part extending above the tentorial notch. The principal regions of the midbrain are the tectum, the cerebral aqueduct, tegmentum, and the cerebral peduncles. Rostral and caudal, Rostrally the midbrain adjoins the diencephalon (thalamus, hypothalamus, etc.), while Rostral and caudal, cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motor Coordination
In physiology, motor coordination is the orchestrated movement of multiple body parts as required to accomplish intended actions, like walking. This coordination is achieved by adjusting kinematic and kinetic parameters associated with each body part involved in the intended movement. The modifications of these parameters typically relies on sensory feedback from one or more sensory modalities (see multisensory integration), such as proprioception and vision. Properties Large degrees of freedom Goal-directed and coordinated movement of body parts is inherently variable because there are many ways of coordinating body parts to achieve the intended movement goal. This is because the degrees of freedom (DOF) is large for most movements due to the many associated neuro- musculoskeletal elements.Bernstein N. (1967). The Coordination and Regulation of Movements. Pergamon Press. New York. Some examples of non-repeatable movements are when pointing or standing up from sitting. Ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parvocellular Red Nucleus
The parvocellular red nucleus (RNp) is located in the rostral midbrain and is involved in motor coordination. Together with the magnocellular red nucleus, it makes up the red nucleus The red nucleus or nucleus ruber is a structure in the rostral midbrain involved in motor coordination. The red nucleus is pale pink, which is believed to be due to the presence of iron in at least two different forms: hemoglobin and ferritin. .... References Midbrain Brainstem nuclei {{neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Nucleus
The red nucleus or nucleus ruber is a structure in the rostral midbrain involved in motor coordination. The red nucleus is pale pink, which is believed to be due to the presence of iron in at least two different forms: hemoglobin and ferritin. The structure is located in the midbrain tegmentum next to the substantia nigra and comprises caudal magnocellular and rostral parvocellular components. The red nucleus and substantia nigra are subcortical centers of the extrapyramidal motor system. Function In a vertebrate without a significant corticospinal tract, gait is mainly controlled by the red nucleus. However, in primates, where the corticospinal tract is dominant, the rubrospinal tract may be regarded as vestigial in motor function. Therefore, the red nucleus is less important in primates than in many other mammals. Nevertheless, the crawling of babies is controlled by the red nucleus, as is arm swinging in typical walking. The red nucleus may play an additional role ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Restless Legs Syndrome
Restless legs syndrome (RLS), also known as Willis–Ekbom disease (WED), is a neurological disorder, usually chronic, that causes an overwhelming urge to move one's legs. There is often an unpleasant feeling in the legs that improves temporarily by moving them. This feeling is often described as aching, tingling, or crawling in nature. Occasionally, arms may also be affected. The feelings generally happen when at rest and therefore can make it hard to sleep. Sleep disruption may leave people with RLS sleepy during the day, with low energy, and irritable or depressed. Additionally, many have limb twitching during sleep, a condition known as periodic limb movement disorder. RLS is not the same as habitual foot-tapping or leg-rocking. Signs and symptoms RLS sensations range from pain or aching in the muscles, to "an itch you can't scratch", a "buzzing sensation", an unpleasant "tickle that won't stop", a "crawling" feeling, or limbs jerking while awake. The sensations typically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma-Aminobutyric Acid
GABA (gamma-aminobutyric acid, γ-aminobutyric acid) is the chief inhibitory neurotransmitter in the developmentally mature mammalian central nervous system. Its principal role is reducing neuronal excitability throughout the nervous system. GABA is sold as a dietary supplement in many countries. It has been traditionally thought that exogenous GABA (i.e., taken as a supplement) does not cross the blood–brain barrier, but data obtained from more recent research (2010s) in rats describes the notion as being unclear. The carboxylate form of GABA is γ-aminobutyrate. Function Neurotransmitter Two general classes of GABA receptor are known: * GABAA receptor, GABAA in which the receptor is part of a ligand-gated ion channel complex * GABAB receptor, GABAB metabotropic receptors, which are G protein-coupled receptors that open or close ion channels via intermediaries (G proteins) Neurons that produce GABA as their output are called GABAergic neurons, and have chiefly inhibito ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutamate (neurotransmitter)
In neuroscience, glutamate is the anion of glutamic acid in its role as a neurotransmitter (a chemical that nerve cells use to send signals to other cells). It is by a wide margin the most abundant excitatory neurotransmitter in the vertebrate nervous system. It is used by every major excitatory function in the vertebrate brain, accounting in total for well over 90% of the synaptic connections in the human brain. It also serves as the primary neurotransmitter for some localized brain regions, such as cerebellum granule cells. Biochemical receptors for glutamate fall into three major classes, known as AMPA receptors, NMDA receptors, and metabotropic glutamate receptors. A fourth class, known as kainate receptors, are similar in many respects to AMPA receptors, but much less abundant. Many synapses use multiple types of glutamate receptors. AMPA receptors are ionotropic receptors specialized for fast excitation: in many synapses they produce excitatory electrical responses in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubrospinal Tract
The rubrospinal tract is one of the descending tracts of the spinal cord. It is a motor control pathway that originates in the red nucleus. It is a part of the lateral indirect extrapyramidal tract. The rubrospinal tract fibers are efferent nerve fibers from the magnocellular part of the red nucleus. (Rubro-olivary fibers are efferents from the parvocelluar part of the red nucleus). It is functionally less important in humans. It is involved in motor control of distal flexors of the upper limbespecially of the hand and fingersby promoting flexor tone while inhibiting extensors. Structure The rubrospinal tract originates in the magnocellular red nucleus in the midbrain, and decussates (crosses over) at the midline in the anterior tegmental decussation. In the pons, it is situated medially within the rostral pontine tegmentum. In the medulla oblongata, it descends within the lateral tegmentum medial to the spinocerebellar tract, and posterior to the spinothalamic tract. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tegmentum Mesencephali
The midbrain is anatomically delineated into the tectum (roof) and the tegmentum (floor). The midbrain tegmentum extends from the substantia nigra to the cerebral aqueduct in a horizontal section of the midbrain. It forms the floor of the midbrain that surrounds below the cerebral aqueduct as well as the floor of the fourth ventricle while the midbrain tectum forms the roof of the fourth ventricle. The tegmentum contains a collection of tracts and nuclei with movement-related, species-specific, and pain-perception functions. The general structures of midbrain tegmentum include red nucleus and the periaqueductal grey matter. Unlike the midbrain tectum (which is a sensory structure located posteriorly), the midbrain tegmentum, which locates anteriorly, is related to a number of motor functions. Within the tegmentum, the red nucleus is in charge of motor coordination (specifically for limb movements) and the periaqueductal gray matter (PAG) contains critical circuits for modulating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boidae
The Boidae, commonly known as boas or boids, are a family of nonvenomous snakes primarily found in the Americas, as well as Africa, Europe, Asia, and some Pacific islands. Boas include some of the world's largest snakes, with the green anaconda of South America being the heaviest and second-longest snake known; in general, adults are medium to large in size, with females usually larger than the males. Six subfamilies comprising 14-15 genera and 54-67 species are currently recognized. Description Like the pythons, boas have elongated supratemporal bones. The quadrate bones are also elongated, but not as much, while both are capable of moving freely so when they swing sideways to their maximum extent, the distance between the hinges of the lower jaw is greatly increased.Parker, H.W.; Grandison, A.G.C. 1977. ''Snakes – A Natural History''. Second Edition. British Museum (Natural History) and Cornell University Press. 108 pp. 16 plates. LCCCN 76-54625. (cloth), (paper). Bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basophilic
Basophilic is a technical term used by pathologists. It describes the appearance of cells, tissues and cellular structures as seen through the microscope after a histological section has been stained with a basic dye. The most common such dye is haematoxylin. The name basophilic refers to the characteristic of these structures to be stained very well by basic dyes. This can be explained by their charges. Basic dyes are cationic, i.e. contain positive charges, and thus they stain anionic structures (i.e. structures containing negative charges), such as the phosphate backbone of DNA in the cell nucleus and ribosomes. "Basophils" are cells that "love" (from greek "-phil") basic dyes, for example haematoxylin, azure and methylene blue. Specifically, this term refers to: * basophil granulocytes * anterior pituitary basophils An abnormal increase in basophil granulocytes is therefore also described as basophilia."Basophilia" ''Collins Online Dictionary'' 2024 https://www.colli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
