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5-HT1A Receptor
The serotonin 1A receptor (or 5-HT1A receptor) is a subtype of serotonin receptor, or 5-HT receptor, that binds serotonin, also known as 5-HT, a neurotransmitter. 5-HT1A is expressed in the brain, spleen, and neonatal kidney. It is a G protein-coupled receptor (GPCR), coupled to the Gi protein, and its activation in the brain mediates hyperpolarisation and reduction of firing rate of the postsynaptic neuron. In humans, the serotonin 1A receptor is encoded by the HTR1A gene. Distribution The 5-HT1A receptor is the most widespread of all the 5-HT receptors. In the central nervous system, 5-HT1A receptors exist in the cerebral cortex, hippocampus, septum, amygdala, and raphe nucleus in high densities, while low amounts also exist in the basal ganglia and thalamus. The 5-HT1A receptors in the raphe nucleus are largely somatodendritic autoreceptors, whereas those in other areas such as the hippocampus are postsynaptic receptors. Function Neuromodulation 5-HT1A recepto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serotonin Receptor
5-HT receptors, 5-hydroxytryptamine receptors, or serotonin receptors, are a group of G protein-coupled receptor and ligand-gated ion channels found in the central and peripheral nervous systems. They mediate both excitatory and inhibitory neurotransmission. The serotonin receptors are activated by the neurotransmitter serotonin, which acts as their natural ligand. The serotonin receptors modulate the release of many neurotransmitters, including glutamate, GABA, dopamine, epinephrine / norepinephrine, and acetylcholine, as well as many hormones, including oxytocin, prolactin, vasopressin, cortisol, corticotropin, and substance P, among others. Serotonin receptors influence various biological and neurological processes such as aggression, anxiety, appetite, cognition, learning, memory, mood, nausea, sleep, and thermoregulation. They are the target of a variety of pharmaceutical and recreational drugs, including many antidepressants, antipsychotics, anorectics, antiemetics, gast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatodendritic
Chemical synapses are biological junctions through which neurons' signals can be sent to each other and to non-neuronal cells such as those in muscles or glands. Chemical synapses allow neurons to form circuits within the central nervous system. They are crucial to the biological computations that underlie perception and thought. They allow the nervous system to connect to and control other systems of the body. At a chemical synapse, one neuron releases neurotransmitter molecules into a small space (the synaptic cleft) that is adjacent to another neuron. The neurotransmitters are contained within small sacs called synaptic vesicles, and are released into the synaptic cleft by exocytosis. These molecules then bind to neurotransmitter receptors on the postsynaptic cell. Finally, the neurotransmitters are cleared from the synapse through one of several potential mechanisms including enzymatic degradation or re-uptake by specific transporters either on the presynaptic cell or on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug
A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via insufflation (medicine), inhalation, drug injection, injection, smoking, ingestion, absorption (skin), absorption via a dermal patch, patch on the skin, suppository, or sublingual administration, dissolution under the tongue. In pharmacology, a drug is a chemical substance, typically of known structure, which, when administered to a living organism, produces a biological effect. A pharmaceutical drug, also called a medication or medicine, is a chemical substance used to pharmacotherapy, treat, cure, preventive healthcare, prevent, or medical diagnosis, diagnose a disease or to promote well-being. Traditionally drugs were obtained through extraction from medicinal plants, but more recently also by organic synthesis. Pharmaceutical drugs may be used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antihypertensive
Antihypertensives are a class of drugs that are used to treat hypertension (high blood pressure). Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke and myocardial infarction. Evidence suggests that reduction of the blood pressure by 5 mmHg can decrease the risk of stroke by 34% and of ischaemic heart disease by 21%, and can reduce the likelihood of dementia, heart failure, and mortality from cardiovascular disease. There are many classes of antihypertensives, which lower blood pressure by different means. Among the most important and most widely used medications are thiazide diuretics, calcium channel blockers, ACE inhibitors, angiotensin II receptor antagonists (ARBs), and beta blockers. Which type of medication to use initially for hypertension has been the subject of several large studies and resulting national guidelines. The fundamental goal of treatment should be the prevention of the important endpoints of hypert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympatholytic
A sympatholytic (or sympathoplegic) drug is a medication that opposes the downstream effects of postganglionic nerve firing in effector organs innervated by the sympathetic nervous system (SNS). They are indicated for various functions; for example, they may be used as antihypertensives. They are also used to treat anxiety, such as generalized anxiety disorder, panic disorder and PTSD. In some cases, such as with Guanfacine, they have also shown to be beneficial in the treatment of ADHD. Mechanisms of action Antiadrenergic agents inhibit the signals of epinephrine and norepinephrine. They are primarily postsynaptic adrenergic receptor antagonists (alpha and beta adrenergic receptor antagonists, or "blockers"), inhibiting the downstream cellular signaling pathways of adrenergic receptors. However, there are exceptions: clonidine is an adrenergic agonist at the α2 receptor; since this receptor is located presynaptically, agonism at this receptor inhibits the presynaptic release of ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rostral Ventrolateral Medulla
The rostral ventrolateral medulla (RVLM), also known as the pressor area of the medulla, is a brain region that is responsible for basal and reflex control of sympathetic activity associated with cardiovascular function. Abnormally elevated sympathetic activity in the RVLM is associated with various cardiovascular diseases, such as heart failure and hypertension. The RVLM is notably involved in the baroreflex. It receives inhibitory GABAergic input from the caudal ventrolateral medulla (CVLM). The RVLM is a primary regulator of the sympathetic nervous system; it sends catecholaminergic projections to the sympathetic preganglionic neurons in the intermediolateral nucleus of the spinal cord via reticulospinal tract. Physostigmine, a choline-esterase inhibitor, elevates endogenous levels of acetylcholine and causes a rise in blood pressure by stimulation of the RVLM. Orexinergic neurons from the lateral hypothalamus output in the RVLM. See also * Vasomotor center The vasomot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vagus Nerve
The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and right vagus nerves—but they are typically referred to collectively as a single subsystem. The vagus is the longest nerve of the autonomic nervous system in the human body and comprises both sensory and motor fibers. The sensory fibers originate from neurons of the nodose ganglion, whereas the motor fibers come from neurons of the dorsal motor nucleus of the vagus and the nucleus ambiguus. The vagus was also historically called the pneumogastric nerve. Structure Upon leaving the medulla oblongata between the olive and the inferior cerebellar peduncle, the vagus nerve extends through the jugular foramen, then passes into the carotid sheath between the internal carotid artery and the internal jugular vein down to the neck, chest, and abdom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vasodilation
Vasodilation is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. The process is the opposite of vasoconstriction, which is the narrowing of blood vessels. When blood vessels dilate, the flow of blood is increased due to a decrease in vascular resistance and increase in cardiac output. Therefore, dilation of arterial blood vessels (mainly the arterioles) decreases blood pressure. The response may be intrinsic (due to local processes in the surrounding tissue) or extrinsic (due to hormones or the nervous system). In addition, the response may be localized to a specific organ (depending on the metabolic needs of a particular tissue, as during strenuous exercise), or it may be systemic (seen throughout the entire systemic circulation). Endogenous substances and drugs that cause vasodilation are termed vasodilators. Such vasoactivity is necessary for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heart Rate
Heart rate (or pulse rate) is the frequency of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm). The heart rate can vary according to the body's physical needs, including the need to absorb oxygen and excrete carbon dioxide, but is also modulated by numerous factors, including, but not limited to, genetics, physical fitness, stress or psychological status, diet, drugs, hormonal status, environment, and disease/illness as well as the interaction between and among these factors. It is usually equal or close to the pulse measured at any peripheral point. The American Heart Association states the normal resting adult human heart rate is 60–100 bpm. Tachycardia is a high heart rate, defined as above 100 bpm at rest. Bradycardia is a low heart rate, defined as below 60 bpm at rest. When a human sleeps, a heartbeat with rates around 40–50 bpm is common and is considered normal. When the heart is not beating in a regular pattern, this is ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Pressure
Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressure" refers to the pressure in the large arteries. Blood pressure is usually expressed in terms of the systolic pressure (maximum pressure during one heartbeat) over diastolic pressure (minimum pressure between two heartbeats) in the cardiac cycle. It is measured in millimeters of mercury ( mmHg) above the surrounding atmospheric pressure. Blood pressure is one of the vital signs—together with respiratory rate, heart rate, oxygen saturation, and body temperature—that healthcare professionals use in evaluating a patient's health. Normal resting blood pressure, in an adult is approximately systolic over diastolic, denoted as "120/80 mmHg". Globally, the average blood pressure, age standardized, has remained about the same since 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuromodulation (medicine)
Neuromodulation is "the alteration of nerve activity through targeted delivery of a stimulus, such as electrical stimulation or chemical agents, to specific neurological sites in the body". It is carried out to normalize – or modulate – nervous tissue function. Neuromodulation is an evolving therapy that can involve a range of electromagnetic stimuli such as a magnetic field (rTMS), an electric current, or a drug instilled directly in the subdural space (intrathecal drug delivery). Emerging applications involve targeted introduction of genes or gene regulators and light (optogenetics), and by 2014, these had been at minimum demonstrated in mammalian models, or first-in-human data had been acquired. The most clinical experience has been with electrical stimulation. Neuromodulation, whether electrical or magnetic, employs the body's natural biological response by stimulating nerve cell activity that can influence populations of nerves by releasing transmitters, such as dopamin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist. Etymology From the Greek αγωνιστής (agōnistēs), contestant; champion; rival < αγων (agōn), contest, combat; exertion, struggle < αγω (agō), I lead, lead towards, conduct; drive Types of agonists can be activated by either endogenous agonists (such as |
