|
Dentate Nucleus
The dentate nucleus refer to a pair of deep cerebellar nuclei deep within the white matter of the cerebellum of the brain with a dentate – tooth-like or serrated – edge. The dentate forms the largest pathway between the cerebellum and the remainder of the brain.Sultan, F., Hamodeh, S., & Baizer, J. S. (2010). THE HUMAN DENTATE NUCLEUS: A COMPLEX SHAPE UNTANGLED. rticle Neuroscience, 167(4), 965–968. It is the largest and most lateral of the four pairs of deep cerebellar nuclei, the others being the globose and emboliform nuclei, which together are referred to as the interposed nucleus, and the fastigial nucleus. The dentate nucleus is responsible for the planning, initiation and control of voluntary movements. The dorsal region of the dentate nucleus contains output channels involved in motor function, which is the movement of skeletal muscle, while the ventral region contains output channels involved in nonmotor function, such as conscious thought and visuospatial fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebellum
The cerebellum (: cerebella or cerebellums; Latin for 'little brain') is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as it or even larger. In humans, the cerebellum plays an important role in motor control and cognition, cognitive functions such as attention and language as well as emotion, emotional control such as regulating fear and pleasure responses, but its movement-related functions are the most solidly established. The human cerebellum does not initiate movement, but contributes to motor coordination, coordination, precision, and accurate timing: it receives input from sensory systems of the spinal cord and from other parts of the brain, and integrates these inputs to fine-tune motor activity. Cerebellar damage produces disorders in fine motor skill, fine movement, sense of balance, equilibrium, list of human positions, posture, and motor learning in humans. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalamus
The thalamus (: thalami; from Greek language, Greek Wikt:θάλαμος, θάλαμος, "chamber") is a large mass of gray matter on the lateral wall of the third ventricle forming the wikt:dorsal, dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all directions, known as the thalamocortical radiations, allowing hub (network science), hub-like exchanges of information. It has several functions, such as the relaying of sensory neuron, sensory and motor neuron, motor signals to the cerebral cortex and the regulation of consciousness, sleep, and alertness. Anatomically, the thalami are paramedian symmetrical structures (left and right), within the vertebrate brain, situated between the cerebral cortex and the midbrain. It forms during embryonic development as the main product of the diencephalon, as first recognized by the Swiss embryologist and anatomist Wilhelm His Sr. in 1893. Anatomy The thalami ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Parietal
The parietal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The parietal lobe is positioned above the temporal lobe and behind the frontal lobe and central sulcus. The parietal lobe integrates sensory information among various modalities, including spatial sense and navigation (proprioception), the main sensory receptive area for the sense of touch in the somatosensory cortex which is just posterior to the central sulcus in the postcentral gyrus, and the dorsal stream of the visual system. The major sensory inputs from the skin (touch, temperature, and pain receptors), relay through the thalamus to the parietal lobe. Several areas of the parietal lobe are important in language processing. The somatosensory cortex can be illustrated as a distorted figure – the cortical homunculus (Latin: "little man") in which the body parts are rendered according to how much of the somatosensory cortex is devoted to them. The superior parietal lobule and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prefrontal Cortex
In mammalian brain anatomy, the prefrontal cortex (PFC) covers the front part of the frontal lobe of the cerebral cortex. It is the association cortex in the frontal lobe. The PFC contains the Brodmann areas BA8, BA9, BA10, BA11, BA12, BA13, BA14, BA24, BA25, BA32, BA44, BA45, BA46, and BA47. This brain region is involved in a wide range of higher-order cognitive functions, including speech formation (Broca's area), gaze ( frontal eye fields), working memory ( dorsolateral prefrontal cortex), and risk processing (e.g. ventromedial prefrontal cortex). The basic activity of this brain region is considered to be orchestration of thoughts and actions in accordance with internal goals. Many authors have indicated an integral link between a person's will to live, personality, and the functions of the prefrontal cortex. This brain region has been implicated in executive functions, such as planning, decision making, working memory, personality expression, moderating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebral Cortex
The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. It is the largest site of Neuron, neural integration in the central nervous system, and plays a key role in attention, perception, awareness, thought, memory, language, and consciousness. The six-layered neocortex makes up approximately 90% of the Cortex (anatomy), cortex, with the allocortex making up the remainder. The cortex is divided into left and right parts by the longitudinal fissure, which separates the two cerebral hemispheres that are joined beneath the cortex by the corpus callosum and other commissural fibers. In most mammals, apart from small mammals that have small brains, the cerebral cortex is folded, providing a greater surface area in the confined volume of the neurocranium, cranium. Apart from minimising brain and cranial volume, gyrification, cortical folding is crucial for the Neural circuit, brain circuitry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premotor
The premotor cortex is an area of the motor cortex lying within the frontal lobe of the brain just anterior to the primary motor cortex. It occupies part of Brodmann's area 6. It has been studied mainly in primates, including monkeys and humans. The functions of the premotor cortex are diverse and not fully understood. It projects directly to the spinal cord and therefore may play a role in the direct control of behavior, with a relative emphasis on the trunk muscles of the body. It may also play a role in planning movement, in the spatial guidance of movement, in the sensory guidance of movement, in understanding the actions of others, and in using abstract rules to perform specific tasks. Different subregions of the premotor cortex have different properties and presumably emphasize different functions. Nerve signals generated in the premotor cortex cause much more complex patterns of movement than the discrete patterns generated in the primary motor cortex. Structure The pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Motor Cortex
The primary motor cortex ( Brodmann area 4) is a brain region that in humans is located in the dorsal portion of the frontal lobe. It is the primary region of the motor system and works in association with other motor areas including premotor cortex, the supplementary motor area, posterior parietal cortex, and several subcortical brain regions, to plan and execute voluntary movements. Primary motor cortex is defined anatomically as the region of cortex that contains large neurons known as Betz cells, which, along with other cortical neurons, send long axons down the spinal cord to synapse onto the interneuron circuitry of the spinal cord and also directly onto the alpha motor neurons in the spinal cord which connect to the muscles. At the primary motor cortex, motor representation is orderly arranged (in an inverted fashion) from the toe (at the top of the cerebral hemisphere) to mouth (at the bottom) along a fold in the cortex called the central sulcus. However, some body p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somata
In cellular neuroscience, the soma (: somata or somas; ), neurocyton, or cell body is the bulbous, non-process portion of a neuron or other brain cell type, containing the cell nucleus. Although it is often used to refer to neurons, it can also refer to other cell types as well, including astrocytes, oligodendrocytes, and microglia. The part of the soma without the nucleus is called perikaryon (: perikarya). There are many different specialized types of neurons, and their sizes vary from as small as about 5 micrometres to over 10 millimetres for some of the smallest and largest neurons of invertebrates, respectively. The soma of a neuron (i.e., the main part of the neuron in which the dendrites branch off of) contains many organelles, including granules called Nissl granules, which are composed largely of rough endoplasmic reticulum and free polyribosomes. The cell nucleus is a key feature of the soma. The nucleus is the source of most of the RNA that is produced in neurons. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendrite
A dendrite (from Ancient Greek language, Greek δένδρον ''déndron'', "tree") or dendron is a branched cytoplasmic process that extends from a nerve cell that propagates the neurotransmission, electrochemical stimulation received from other neural cells to the cell body, or soma (biology), soma, of the neuron from which the dendrites project. Electrical stimulation is transmitted onto dendrites by upstream neurons (usually via their axons) via synapses which are located at various points throughout the dendritic tree. Dendrites play a critical role in integrating these synaptic inputs and in determining the extent to which action potentials are produced by the neuron. Structure and function Dendrites are one of two types of cytoplasmic processes that extrude from the cell body of a neuron, the other type being an axon. Axons can be distinguished from dendrites by several features including shape, length, and function. Dendrites often taper off in shape and are shorter, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pontine Nuclei
The pontine nuclei (or griseum pontis) are all the neurons of the ventral pons. Corticopontine fibres project from the primary motor cortex to the ipsilateral pontine nucleus; pontocerebellar fibers then relay the information to the contralateral cerebellum via the middle cerebellar peduncle. They are involved in motor function: the pontine nuclei are involved in adjusting movements according to their outcome (movement error correction), and are therefore important in learning motor skills. Anatomy The pontine nuclei encompass all of the about 20 million neurons scattered throughout the basilar part of pons. The pontine nuclei nuclei extend caudally into the medulla oblongata as the arcuate nucleus which is functionally homologous with the pontine nuclei. Afferents Corticopontine fibres arise primarily from the neocortex layer V of the premotor, somatosensory, non- striate visual, posterior parietal, and cingulate cerebral cortex; there are also a few fibers originating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Reticular Nucleus
The lateral reticular nucleus, of the lateral funiculus, can be divided into three subnuclei, the parvocellular, magnocellular and the ''subtrigeminal''. As is typical of the reticular formation, none of these are very distinct subnuclei, but rather blurred distinctions between cell types and location. The lateral reticular nucleus sends all of its projections to the cerebellum. * The parvocellular portion of the LRN and the immediately adjacent magnocellular portion send most their projections to the vermis of the cerebellum. The rest of the magnocellular subnucleus sends its projections to the hemisphere regions of the cerebellum. * The subtrigeminal nucleus sends its projections to the flocculonodular lobe. All of these efferent pathways are projected in an ipsilateral Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Olive
The inferior olivary nucleus (ION) is a structure found in the medulla oblongata underneath the superior olivary nucleus.Gado, Thomas A. Woolsey; Joseph Hanaway; Mokhtar H. (2003). The brain atlas a visual guide to the human central nervous system (2nd ed.). Hoboken, NJ: Wiley. p. 206. . In vertebrates, the ION is known to coordinate signals from the spinal cord to the cerebellum to regulate motor coordination and learning.Schweighofer N, Lang EJ, Kawato M. Role of the olivo-cerebellar complex in motor learning and control. ''Frontiers in Neural Circuits''. 2013;7:94. . These connections have been shown to be tightly associated, as degeneration of either the cerebellum or the ION results in degeneration of the other. Neurons of the ION are glutamatergic and receive inhibitory input via GABA receptors. There are two distinct GABAα receptor populations that are spatially organized within each neuron present in the ION. The GABAα receptor make-up varies based on where the rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
