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Ventral Anterior Nucleus
The ventral anterior nucleus (VA) is a nucleus in the ventral nuclear group of the thalamus. It acts with the anterior part of the ventral lateral nucleus to modify signals from the basal ganglia. Inputs and outputs The ventral anterior nucleus receives neuronal inputs from the basal ganglia. Its main afferent fibres are from the globus pallidus. The efferent fibres from this nucleus pass into the premotor cortex 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 human ... for initiation and planning of movement. Functions It helps to function in movement by providing feedback for the outputs of the basal ganglia. Additional images File:Constudthal.gif, Thalamus File:Territoriostalamo.svg, Thalamus References {{DEFAULTSORT:Ventral Anterior Nucleus Thalamus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalamic Nuclei
This traditional list does not accord strictly with human thalamic anatomy. Nuclear groups of the thalamus include: * anterior nuclear group (anteroventral, anterodorsal, anteromedial) *medial nuclear group (medial dorsal nucleus, dorsomedial) ** parvocellular part ( parvicellular part) ** magnocellular part *midline nuclear group or paramedian **paratenial nucleus **paraventricular thalamus ** reuniens nucleus ( medioventral nucleus) **rhomboidal nucleus ** interanteromedial ** intermediodorsal * intralaminar nuclear group **anterior (rostral) group *** paracentral nucleus *** central lateral nucleus *** central medial nucleus (''not'' called "centromedial") **posterior (caudal) intralaminar group ***centromedian nucleus *** parafascicular nucleus *lateral nuclear group is replaced by **posterior region *** pulvinar **** anterior pulvinar nucleus **** lateral pulvinar nucleus **** medial pulvinar nucleus **** inferior pulvinar nucleus *** lateral posterior nucleus belongs to pulv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medial Geniculate Nucleus
The medial geniculate nucleus (MGN) or medial geniculate body (MGB) is part of the auditory thalamus and represents the thalamic relay between the inferior colliculus (IC) and the auditory cortex (AC). It is made up of a number of sub-nuclei that are distinguished by their neuronal morphology and density, by their afferent and efferent connections, and by the coding properties of their neurons. It is thought that the MGN influences the direction and maintenance of attention. Divisions The MGN has three major divisions; ventral (VMGN), dorsal (DMGN) and medial (MMGN). Whilst the VMGN is specific to auditory information processing, the DMGN and MMGN also receive information from non-auditory pathways. Ventral subnucleus Cell types There are two main cell types in the ventral subnucleus of the medial geniculate body (VMGN): * Thalamocortical relay cells (or principal neurons): The dendritic input to these cells comes from two sets of dendritic trees oriented on opposite poles of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Efferent Nerve Fiber
Efferent nerve fibers are axons (nerve fibers) of efferent neurons that exit a particular region. These terms have a slightly different meaning in the context of the peripheral nervous system (PNS) and central nervous system (CNS). The efferent fiber is a long process projecting far from the neuron's body that carries nerve impulses away from the central nervous system toward the peripheral effector organs (muscles and glands). A bundle of these fibers constitute an efferent nerve. The opposite direction of neural activity is afferent conduction, which carries impulses by way of the afferent nerve fibers of sensory neurons. In the nervous system, there is a "closed loop" system of sensation, decision, and reactions. This process is carried out through the activity of sensory neurons, interneurons, and motor neurons. In the CNS, afferent and efferent projections can be from the perspective of any given brain region. That is, each brain region has its own unique set of affe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Globus Pallidus
The globus pallidus (GP), also known as paleostriatum or dorsal pallidum, is a major component of the Cerebral cortex, subcortical basal ganglia in the brain. It consists of two adjacent segments, one external (or lateral), known in rodents simply as the globus pallidus, and one internal (or medial). 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 receives 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 synapse, synaptology. Neither receives direct cortical afferents, and both receive substantial additional inputs from the intralaminar thalamic nuclei. Globus pallidus is Latin for "pale globe". Structure Pallidal nuclei are made up of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afferent Nerve Fiber
Afferent nerve fibers are axons (nerve fibers) of sensory neurons that carry sensory information from sensory receptors to the central nervous system. Many afferent projections ''arrive'' at a particular brain region. In the peripheral nervous system, afferent nerve fibers are part of the sensory nervous system and arise from outside of the central nervous system. Sensory and mixed nerves contain afferent fibers. Structure Afferent neurons are pseudounipolar neurons that have a single process leaving the cell body dividing into two branches: the long one towards the sensory organ, and the short one toward the central nervous system (e.g. spinal cord). These cells do have sensory afferent dendrites, similar to those typically inherent in neurons. They have a smooth and rounded cell body located in the ganglia of the peripheral nervous system. Just outside the spinal cord, thousands of afferent neuronal cell bodies are aggregated in a swelling in the dorsal root known a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal Ganglia
The basal ganglia (BG) or basal nuclei are a group of subcortical Nucleus (neuroanatomy), nuclei found in the brains of vertebrates. In humans and other primates, differences exist, primarily in the division of the globus pallidus into external and internal regions, and in the division of the striatum. Positioned at the base of the forebrain and the top of the midbrain, they have strong connections with the cerebral cortex, thalamus, brainstem and other brain areas. The basal ganglia are associated with a variety of functions, including regulating voluntary motor control, motor movements, procedural memory, procedural learning, habituation, habit formation, conditional learning, eye movements, cognition, and emotion. The main functional components of the basal ganglia include the striatum, consisting of both the dorsal striatum (caudate nucleus and putamen) and the ventral striatum (nucleus accumbens and olfactory tubercle), the globus pallidus, the ventral pallidum, the substa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventral Lateral Nucleus
The ventral lateral nucleus (VL) is a nucleus in the ventral nuclear group of the thalamus. Inputs and outputs It receives neuronal inputs from the basal ganglia which includes the substantia nigra and the globus pallidus (via the thalamic fasciculus). It also has inputs from the cerebellum (via the dentatothalamic tract). It sends neuronal output to the primary motor cortex and premotor cortex. The ventral lateral nucleus in the thalamus forms the motor functional division in the thalamic nuclei along with the ventral anterior nucleus. The ventral lateral nucleus receives motor information from the cerebellum and the globus pallidus. Output from the ventral lateral nucleus then goes to the primary motor cortex. Functions The function of the ventral lateral nucleus is to target efferents including the motor cortex, premotor cortex, and supplementary motor cortex. Therefore, its function helps the coordination and planning of movement. It also plays a role in the learn ... [...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] |
Ventral Nuclear Group
The ventral nuclear group is a collection of nuclei on the ventral side of the 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 ..., it consists of the following: * ventral anterior nucleus * ventral lateral nucleus * ventral posterior nucleus – this is made up of two nuclei: the ventral posterolateral nucleus and the ventral posteromedial nucleus See also * Anterolateral region of the motor thalamus References Thalamus {{Neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleus (neuroanatomy)
In neuroanatomy, a nucleus (: nuclei) is a cluster of neurons in the central nervous system, located deep within the cerebral hemispheres and brainstem. The neurons in one nucleus usually have roughly similar connections and functions. Nuclei are connected to other nuclei by tracts, the bundles (fascicles) of axons (nerve fibers) extending from the cell bodies. A nucleus is one of the two most common forms of nerve cell organization, the other being layered structures such as the cerebral cortex or cerebellar cortex. In anatomical sections, a nucleus shows up as a region of gray matter, often bordered by white matter. The vertebrate brain contains hundreds of distinguishable nuclei, varying widely in shape and size. A nucleus may itself have a complex internal structure, with multiple types of neurons arranged in clumps (subnuclei) or layers. The term "nucleus" is in some cases used rather loosely, to mean simply an identifiably distinct group of neurons, even if they are sprea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Geniculate Nucleus
In neuroanatomy, the lateral geniculate nucleus (LGN; also called the lateral geniculate body or lateral geniculate complex) is a structure in the thalamus and a key component of the mammalian visual pathway. It is a small, ovoid, Anatomical terms of location#Dorsal_and_ventral, ventral projection of the thalamus where the thalamus connects with the optic nerve. There are two LGNs, one on the left and another on the right side of the thalamus. In humans, both LGNs have six layers of neurons (grey matter) alternating with optic fibers (white matter). The LGN receives information directly from the ascending retinal ganglion cells via the optic tract and from the reticular activating system. Neurons of the LGN send their axons through the optic radiation, a direct pathway to the primary visual cortex. In addition, the LGN receives many strong feedback connections from the primary visual cortex. In humans as well as other mammals, the two strongest pathways linking the eye to the bra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midline Nuclear Group
The midline nuclear group (or midline thalamic nuclei) is a region of the thalamus consisting of the following nuclei: * Paraventricular thalamus, paraventricular nucleus of thalamus (''nucleus paraventricularis thalami'') - not to be confused with paraventricular nucleus of hypothalamus * paratenial nucleus (''nucleus parataenialis'') * nucleus reuniens (also known as the medioventral nucleus) * rhomboidal nucleus (''nucleus commissuralis rhomboidalis'') * subfascicular nucleus (''nucleus subfascicularis'') The List of regions in the human brain#Thalamus, midline nuclei are often called "nonspecific" in that they project widely to the cortex and elsewhere. This has led to the assumption that they may be involved in general functions such as alerting. However, anatomical connections might suggest more specific functions, with the paraventricular and paratenial nuclei involved in viscero-limbic functions, and the reuniens and rhomboid nuclei involved in multimodal sensory processin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
