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Plateau Potentials
Plateau potentials, caused by persistent inward currents (PICs), are a type of electrical behavior seen in neurons. Spinal Cord Plateau potentials are of particular importance to spinal cord motor systems. PICs are set up by the influence of descending monoaminergic reticulospinal pathways. Metabotropic neurotransmitters, via monoaminergic input such as 5-HT and norepinephrine, modulate the activity of dendritic L-type Calcium channels that allow a sustained, positive, inward current into the cell. This leads to a lasting depolarisation. In this state, the cell fires action potentials independent of synaptic input. The PICs can be turned off via the activation of high-frequency inhibitory input at which point the cell returns to a resting state. Olfactory Bulb Periglomerular cells, inhibitory interneuron Interneurons (also called internuncial neurons, relay neurons, association neurons, connector neurons, intermediate neurons or local circuit neurons) are neurons that con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurons
A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. Non-animals like plants and fungi do not have nerve cells. Neurons are typically classified into three types based on their function. Sensory neurons respond to stimuli such as touch, sound, or light that affect the cells of the sensory organs, and they send signals to the spinal cord or brain. Motor neurons receive signals from the brain and spinal cord to control everything from muscle contractions to glandular output. Interneurons connect neurons to other neurons within the same region of the brain or spinal cord. When multiple neurons are connected together, they form what is called a neural circuit. A typical neuron consists of a cell body (soma), dendrites, and a single axon. The soma is a compact structure, and the axon and dend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinal Cord
The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the spinal cord, which contains cerebrospinal fluid. The brain and spinal cord together make up the central nervous system (CNS). In humans, the spinal cord begins at the occipital bone, passing through the foramen magnum and then enters the spinal canal at the beginning of the cervical vertebrae. The spinal cord extends down to between the first and second lumbar vertebrae, where it ends. The enclosing bony vertebral column protects the relatively shorter spinal cord. It is around long in adult men and around long in adult women. The diameter of the spinal cord ranges from in the cervical and lumbar regions to in the thoracic area. The spinal cord functions primarily in the transmission of nerve signals from the motor cortex to the body, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoaminergic
Monoaminergic means "working on monoamine neurotransmitters", which include serotonin, dopamine, norepinephrine, epinephrine, and histamine. A monoaminergic, or monoaminergic drug, is a chemical, which functions to directly modulate the serotonin, dopamine, norepinephrine, epinephrine, and/or histamine neurotransmitter systems in the brain. Monoaminergics include catecholaminergics (which can be further divided into adrenergics and dopaminergics), serotonergics, and histaminergics. Examples of monoaminergic drugs include monoamine precursors, monoamine receptor modulators, monoamine reuptake inhibitors, monoamine releasing agents, and monoamine metabolism modulators such as monoamine oxidase inhibitors. See also * Adenosinergic * Adrenergic * Cannabinoidergic * Cholinergic * Dopaminergic * GABAergic * Glycinergic * Histaminergic * Melatonergic * Opioidergic * Serotonergic Serotonergic () or serotoninergic () means "pertaining to or affecting serotonin". Serotonin is a neurotran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reticulospinal
The reticular formation is a set of interconnected nuclei that are located throughout the brainstem. It is not anatomically well defined, because it includes neurons located in different parts of the brain. The neurons of the reticular formation make up a complex set of networks in the core of the brainstem that extend from the upper part of the midbrain to the lower part of the medulla oblongata. The reticular formation includes ascending pathways to the cortex in the ascending reticular activating system (ARAS) and descending pathways to the spinal cord via the reticulospinal tracts. Neurons of the reticular formation, particularly those of the ascending reticular activating system, play a crucial role in maintaining behavioral arousal and consciousness. The overall functions of the reticular formation are modulatory and premotor, involving somatic motor control, cardiovascular control, pain modulation, sleep and consciousness, and habituation. The modulatory functions are prim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT
Serotonin () or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter. Its biological function is complex and multifaceted, modulating mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vasoconstriction. Approximately 90% of the serotonin that the body produces is in the intestinal tract. Biochemically, the indoleamine molecule derives from the amino acid tryptophan, via the (rate-limiting) hydroxylation of the 5 position on the ring (forming the intermediate 5-hydroxytryptophan), and then decarboxylation to produce serotonin. Serotonin is primarily found in the enteric nervous system located in the gastrointestinal tract (GI tract). However, it is also produced in the central nervous system (CNS), specifically in the raphe nuclei located in the brainstem, Merkel cells located in the skin, pulmonary neuroendocrine cells and taste receptor cells in the tongue. Additionally, serotonin is stored in blood platelets and is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norepinephrine
Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as both a hormone and neurotransmitter. The name "noradrenaline" (from Latin '' ad'', "near", and '' ren'', "kidney") is more commonly used in the United Kingdom, whereas "norepinephrine" (from Ancient Greek ἐπῐ́ (''epí''), "upon", and νεφρός (''nephrós''), "kidney") is usually preferred in the United States. "Norepinephrine" is also the international nonproprietary name given to the drug. Regardless of which name is used for the substance itself, parts of the body that produce or are affected by it are referred to as noradrenergic. The general function of norepinephrine is to mobilize the brain and body for action. Norepinephrine release is lowest during sleep, rises during wakefulness, and reaches much higher levels during situations of stress or danger, in the so-called fight-or-flight response. In the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depolarisation
In biology, depolarization or hypopolarization is a change within a cell, during which the cell undergoes a shift in electric charge distribution, resulting in less negative charge inside the cell compared to the outside. Depolarization is essential to the function of many cells, communication between cells, and the overall physiology of an organism. Most cells in higher organisms maintain an internal environment that is negatively charged relative to the cell's exterior. This difference in charge is called the cell's membrane potential. In the process of depolarization, the negative internal charge of the cell temporarily becomes more positive (less negative). This shift from a negative to a more positive membrane potential occurs during several processes, including an action potential. During an action potential, the depolarization is so large that the potential difference across the cell membrane briefly reverses polarity, with the inside of the cell becoming positively charg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Action Potentials
An action potential occurs when the membrane potential of a specific cell location rapidly rises and falls. This depolarization then causes adjacent locations to similarly depolarize. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and in some plant cells. Certain endocrine cells such as pancreatic beta cells, and certain cells of the anterior pituitary gland are also excitable cells. In neurons, action potentials play a central role in cell-cell communication by providing for—or with regard to saltatory conduction, assisting—the propagation of signals along the neuron's axon toward synaptic boutons situated at the ends of an axon; these signals can then connect with other neurons at synapses, or to motor cells or glands. In other types of cells, their main function is to activate intracellular processes. In muscle cells, for example, an action potential is the first step in the chain of events leadi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periglomerular Cells
Periglomerular cells mediate lateral inhibition in the olfactory system together with granule cells. They have inhibitory synapses on mitral cells and tufted cell Tufted cells are found within the olfactory glomeruli. They receive input from the receptor cells of the olfactory epithelium found in areas of the nose able to sense smell. Both tufted cells and mitral cells are called projection neurons. Projecti ...s. References Olfactory system Neurons {{neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inhibitory Neurotransmission
An inhibitory postsynaptic potential (IPSP) is a kind of synaptic potential that makes a postsynaptic neuron less likely to generate an action potential.Purves et al. Neuroscience. 4th ed. Sunderland (MA): Sinauer Associates, Incorporated; 2008. IPSP were first investigated in motorneurons by David P. C. Lloyd, John Eccles and Rodolfo Llinás in the 1950s and 1960s. The opposite of an inhibitory postsynaptic potential is an excitatory postsynaptic potential (EPSP), which is a synaptic potential that makes a postsynaptic neuron ''more'' likely to generate an action potential. IPSPs can take place at all chemical synapses, which use the secretion of neurotransmitters to create cell to cell signalling. Inhibitory presynaptic neurons release neurotransmitters that then bind to the postsynaptic receptors; this induces a change in the permeability of the postsynaptic neuronal membrane to particular ions. An electric current that changes the postsynaptic membrane potential to create a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interneuron
Interneurons (also called internuncial neurons, relay neurons, association neurons, connector neurons, intermediate neurons or local circuit neurons) are neurons that connect two brain regions, i.e. not direct motor neurons or sensory neurons. Interneurons are the central nodes of neural circuits, enabling communication between sensory or motor neurons and the central nervous system (CNS). They play vital roles in reflexes, neuronal oscillations, and neurogenesis in the adult mammalian brain. Interneurons can be further broken down into two groups: local interneurons and relay interneurons. Local interneurons have short axons and form circuits with nearby neurons to analyze small pieces of information. Relay interneurons have long axons and connect circuits of neurons in one region of the brain with those in other regions. However, interneurons are generally considered to operate mainly within local brain areas. The interaction between interneurons allow the brain to perform c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glomerulus (olfaction)
The glomerulus (plural glomeruli) is a spherical structure located in the olfactory bulb of the brain where synapses form between the terminals of the olfactory nerve and the dendrites of mitral, periglomerular and tufted cells. Each glomerulus is surrounded by a heterogeneous population of juxtaglomerular neurons (that include periglomerular, short axon, and external tufted cells) and glial cells. All glomeruli are located near the surface of the olfactory bulb. The olfactory bulb also includes a portion of the anterior olfactory nucleus, the cells of which contribute fibers to the olfactory tract. They are the initial sites for synaptic processing of odor information coming from the nose. A glomerulus is made up of a globular tangle of axons from the olfactory receptor neurons, and dendrites from the mitral and tufted cells, as well as, from cells that surround the glomerulus such as the external tufted cells, periglomerular cells, short axon cells, and astrocytes. In mammals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
