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Zona Incerta
The zona incerta (ZI) is a horizontally elongated small Nucleus (neuroanatomy), nucleus that separates the larger subthalamic nucleus from 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 ... [...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] |
Thalamic Reticular Nucleus
The thalamic reticular nucleus is part of the ventral thalamus that forms a capsule around the thalamus laterally. However, recent evidence from mice and fish question this statement and define it as a dorsal thalamic structure. It is separated from the thalamus by the external medullary lamina. Reticular nucleus cells are all GABAergic, and have discoid dendritic arbors in the plane of the nucleus. Thalamic Reticular Nucleus is variously abbreviated TRN, RTN, NRT, and RT. The TRN is found in all mammals. Input and output The thalamic reticular nucleus receives input from the cerebral cortex and dorsal thalamic nuclei. Most input comes from collaterals of fibers passing through the thalamic reticular nucleus. The outputs from the primary thalamic reticular nucleus project to dorsal thalamic nuclei, but never to the cerebral cortex. This is the only thalamic nucleus that does not project to the cerebral cortex. Instead it modulates the information from other nuclei in the thala ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brainstem
The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is continuous with the thalamus of the diencephalon through the tentorial notch, and sometimes the diencephalon is included in the brainstem. The brainstem is very small, making up around only 2.6 percent of the brain's total weight. It has the critical roles of regulating heart and respiratory system, respiratory function, helping to control heart rate and breathing rate. It also provides the main motor and sensory nerve supply to the face and neck via the cranial nerves. Ten pairs of cranial nerves come from the brainstem. Other roles include the regulation of the central nervous system and the body's sleep cycle. It is also of prime importance in the conveyance of motor and sensory pathways from the rest of the brain to the body, and from the b ... [...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] |
Diencephalon
In the human brain, the diencephalon (or interbrain) is a division of the forebrain (embryonic ''prosencephalon''). It is situated between the telencephalon and the midbrain (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 brain vesicle, vesicles of the brain formed during human embryonic development, embryonic development. During the third week of development a neural tube is created from the ectoderm, one of the three primary germ layers, and forms three main vesicles: the prosencephalon, the Midbrain, mesencephalon and the Hindbrain, rhombencephalon. The prosencephalon gradually divides into the telencephalon (the cerebrum) and the diencephalon. Structure The diencephalon consists of the following structures: * Thalamus * Hypothalamus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanocyte Stimulating Hormone
The melanocyte-stimulating hormones, known collectively as MSH, also known as melanotropins or intermedins, are a family of peptide hormones and neuropeptides consisting of α-melanocyte-stimulating hormone (α-MSH), β-melanocyte-stimulating hormone (β-MSH), and γ-melanocyte-stimulating hormone (γ-MSH) that are produced by cells in the pars intermedia of the anterior lobe of the pituitary gland. Synthetic analogues of α-MSH, such as afamelanotide (melanotan I; Scenesse), melanotan II, and bremelanotide (PT-141), have been developed and researched. Biosynthesis The various forms of MSH are generated from different cleavages of the proopiomelanocortin protein, which also yields other important neuropeptides like adrenocorticotropic hormone. Melanocytes in skin make and secrete MSH in response to ultraviolet light, where it increases synthesis of melanin. Some neurons in arcuate nucleus of the hypothalamus make and secrete α-MSH in response to leptin; α-MSH is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angiotensin II
Angiotensin is a peptide hormone that causes vasoconstriction and an increase in blood pressure. It is part of the renin–angiotensin system, which regulates blood pressure. Angiotensin also stimulates the release of aldosterone from the adrenal cortex to promote sodium retention by the kidneys. An oligopeptide, angiotensin is a hormone and a dipsogen. It is derived from the precursor molecule angiotensinogen, a serum globulin produced in the liver. Angiotensin was isolated in the late 1930s (first named "angiotonin" or "hypertensin", later renamed "angiotensin" as a consensus by the 2 groups that independently discovered it) and subsequently characterized and synthesized by groups at the Cleveland Clinic and Ciba laboratories. Precursor and types Angiotensinogen Angiotensinogen is an α-2-globulin synthesized in the liver and is a precursor for angiotensin, but has also been indicated as having many other roles not related to angiotensin peptides. It is a me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatostatin
Somatostatin, also known as growth hormone-inhibiting hormone (GHIH) or by #Nomenclature, several other names, is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G protein-coupled somatostatin receptors and inhibition of the release of numerous secondary hormones. Somatostatin inhibits insulin and glucagon secretion. Somatostatin has two active forms produced by the alternative cleavage of a single preproprotein: one consisting of 14 amino acids (shown in infobox to right), the other consisting of 28 amino acids. Among the vertebrates, there exist six different somatostatin genes that have been named: ''SS1'', ''SS2'', ''SS3'', ''SS4'', ''SS5'' and ''SS6''. Zebrafish have all six. The six different genes, along with the five different somatostatin receptors, allow somatostatin to possess a large range of functions. Humans have only one somatostatin gene, ''SST''. Nomenclature Synonyms of "somatost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopaminergic
Dopaminergic means "related to dopamine" (literally, "working on dopamine"), a common neurotransmitter. Dopaminergic substances or actions increase dopamine-related activity in the brain. Dopaminergic pathways, Dopaminergic brain pathways facilitate dopamine-related activity. For example, certain proteins such as the dopamine transporter (DAT), vesicular monoamine transporter 2 (VMAT2), and dopamine receptors can be classified as dopaminergic, and neurons that Biosynthesis, synthesize or contain dopamine and synapses with dopamine receptors in them may also be labeled as ''dopaminergic''. Enzymes that regulate the biosynthesis or metabolism of dopamine such as aromatic L-amino acid decarboxylase or DOPA decarboxylase, monoamine oxidase (MAO), and catechol-O-methyl transferase, catechol ''O''-methyl transferase (COMT) may be referred to as ''dopaminergic'' as well. Also, any endogenous or exogenous chemical substance that acts to affect dopamine receptors or dopamine release thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanin Concentrating Hormone
Melanin-concentrating hormone (MCH), also known as pro-melanin stimulating hormone (PMCH), is a cyclic 19-amino acid orexigenic hypothalamic peptide originally isolated from the pituitary gland of teleost fish, where it controls skin pigmentation. In mammals it is involved in the regulation of feeding behavior, mood, sleep-wake cycle and energy balance. Structure MCH is a cyclic 19-amino acid neuropeptide, as it is a polypeptide chain that is able to act as a neurotransmitter. MCH neurons are mainly concentrated in the lateral hypothalamic area, zona incerta, and the incerto-hypothalamic area, but they are also located, in much smaller amounts, in the paramedian pontine reticular formation (PPRF), medial preoptic area, laterodorsal tegmental nucleus, and the olfactory tubercle. MCH is activated by binding to two G-coupled protein receptors ( GCPRs), MCHR1 and MCHR2. MCHR2 has only been identified in certain species such as humans, dogs, ferrets, and rhesus monkeys, while ... [...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] |
Lateral Inhibition
In neurobiology, lateral inhibition is the capacity of an excited neuron to reduce the activity of its neighbors. Lateral inhibition disables the spreading of action potentials An action potential (also known as a nerve impulse or "spike" when in a neuron) is a series of quick changes in voltage across a cell membrane. An action potential occurs when the membrane potential of a specific cell rapidly rises and falls. ... from excited neurons to neighboring neurons in the lateral direction. This creates a contrast in stimulation that allows increased sensory perception. It is also referred to as lateral antagonism and occurs primarily in visual processes, but also in Touch, tactile, Auditory system, auditory, and even olfactory processing. Cells that utilize lateral inhibition appear primarily in the cerebral cortex and thalamus and make up lateral inhibitory networks (LINs). Artificial lateral inhibition has been incorporated into artificial sensory systems, such as vision c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
