Neurotransmitter 3D Animation
on Tuesday, December 21, 2010




Neurotransmitters are endogenous chemicals which transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to receptors in the membrane on the postsynaptic side of the synapse. Release of neurotransmitters usually follows arrival of an action potential at the synapse, but may also follow graded electrical potentials. Low level "baseline" release also occurs without electrical stimulation. Neurotransmitters are synthesized from plentiful and simple precursors, such as amino acids, which are readily available from the diet and which require only a small number of biosynthetic steps to convert. The chemical identity of neurotransmitters is often difficult to determine experimentally. For example, it is easy using an electron microscope to recognize vesicles on the presynaptic side of a synapse, but it may not be easy to determine directly what chemical is packed into them. The difficulties led to many historical controversies over whether a given chemical was or was not clearly established as a transmitter. In an effort to give some structure to the arguments, neurochemists worked out a set of experimentally tractable rules. According to the prevailing beliefs of the 1960s, a chemical can be classified as a neurotransmitter if it meets the following conditions: * There are precursors and/or synthesis enzymes located in the presynaptic side of the synapse. * The chemical is present in the presynaptic element. * It is available in sufficient quantity in the presynaptic neuron to affect the postsynaptic neuron; * There are postsynaptic receptors and the chemical is able to bind to them. * A biochemical mechanism for inactivation is present. There are many different ways to classify neurotransmitters. Dividing them into amino acids, peptides, and monoamines is sufficient for some classification purposes. Major neurotransmitters: * Amino acids: glutamate, aspartate, D-serine, γ-aminobutyric acid (GABA), glycine * Monoamines and other biogenic amines: dopamine (DA), norepinephrine (noradrenaline; NE, NA), epinephrine (adrenaline), histamine, serotonin (SE, 5-HT), melatonin * Others: acetylcholine (ACh), adenosine, anandamide, nitric oxide, etc. In addition, over 50 neuroactive peptides have been found, and new ones are discovered regularly. Many of these are "co-released" along with a small-molecule transmitter, but in some cases a peptide is the primary transmitter at a synapse. β-endorphin is a relatively well known example of a peptide neurotransmitter; it engages in highly specific interactions with opioid receptors in the central nervous system. Single ions, such as synaptically released zinc, are also considered neurotransmitters by some[by whom?], as are some gaseous molecules such as nitric oxide (NO) and carbon monoxide (CO). These are not classical neurotransmitters by the strictest definition, however, because although they have all been shown experimentally to be released by presynaptic terminals in an activity-dependent way, they are not packaged into vesicles. By far the most prevalent transmitter is glutamate, which is excitatory at well over 90% of the synapses in the human brain. The next most prevalent is GABA, which is inhibitory at more than 90% of the synapses that do not use glutamate. Even though other transmitters are used in far fewer synapses, they may be very important functionally—the great majority of psychoactive drugs exert their effects by altering the actions of some neurotransmitter systems, often acting through transmitters other than glutamate or GABA. Addictive drugs such as cocaine and amphetamine exert their effects primarily on the dop

Are you seeking sinus, allergy, or nasal congestion relief? Nasal irrigation, also known as nasal rinsining, is your solution! Nasal Care's nasal irrigation system is an all-natural, simple, and easy sinus and allergy treatment that brings gentle and soothing sinus relief. Visit www.nasalcleanse.com to learn more about the safe, simple and all-natural relief you can experience with NasalCare's nasal irrigation system.

Transmetatarsal Amputation for Gangrene

Rubber band ligation is a procedure in which the hemorrhoid is tied off at its base with rubber bands, cutting off the blood flow to the hemorrhoid. This treatment is only for internal hemorrhoids. To do this procedure, a doctor inserts a viewing instrument (anoscope) into the anus. The hemorrhoid is grasped with an instrument, and a device places a rubber band around the base of the hemorrhoid. The hemorrhoid then shrinks and dies and, in about a week, falls off. A scar will form in place of the hemorrhoid, holding nearby veins so they don't bulge into the anal canal. The procedure is done in a doctor's office. You will be asked whether the rubber bands feel too tight. If the bands are extremely painful, a medicine may be injected into the banded hemorrhoids to numb them. After the procedure, you may feel pain and have a sensation of fullness in the lower abdomen. Or you may feel as if you need to have a bowel movement. Treatment is limited to 1 to 2 hemorrhoids at a time if done in the doctor's office. Several hemorrhoids may be treated at one time if the person has general anesthesia. Additional areas may be treated at 4- to 6-week intervals.

Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium. As the atrium contracts, blood flows from your right atrium into your right ventricle through the open tricuspid valve.

Rheum is made up of mucus, skin cells, oils and dust. The rheum that comes from the eyes and forms eye boogers is called gound, which you may know as eye sand, eye gunk, sleep dust, sleep sand, sleep in your eyes, or eye shnooters. When you're awake, gound doesn't cause any problems.

How Respiratory Pump Affects Venous Return

How to diagnose digital ulceration in out patient clinic.

Traditional Chinese fire cupping therapy

Learn about the exciting results Baptist Healthcare System is experiencing with McKesson enterprise intelligence solutions in this video testimonial.

Pancreatitis is inflammation of the pancreas. The pancreas is a gland located behind the stomach. It releases the hormones, insulin and glucagon, as well as digestive enzymes that help you digest and absorb food.

A rare video showing the flail chest which is traumatic condition during which the chest wall shows paradoxical movement i.e. in with expiration and out with inspiration

Watch that video of The Most Amazing Plastic Surgeries

Sinusitis means your sinuses are inflamed. The cause can be an infection or another problem. Your sinuses are hollow air spaces within the bones surrounding the nose. They produce mucus, which drains into the nose. If your nose is swollen, this can block the sinuses and cause pain. There are several types of sinusitis, including Acute, which lasts up to 4 weeks Subacute, which lasts 4 to 12 weeks Chronic, which lasts more than 12 weeks and can continue for months or even years Recurrent, with several attacks within a year Acute sinusitis often starts as a cold, which then turns into a bacterial infection. Allergies, nasal problems, and certain diseases can also cause acute and chronic sinusitis. Symptoms of sinusitis can include fever, weakness, fatigue, cough, and congestion. There may also be mucus drainage in the back of the throat, called postnasal drip. Your health care professional diagnoses sinusitis based on your symptoms and an examination of your nose and face. You may also need imaging tests. Treatments include antibiotics, decongestants, and pain relievers. Using heat pads on the inflamed area, saline nasal sprays, and vaporizers can also help.

Osteochondroma. Osteochondromas (osteocartilaginous exostoses), the most common benign bone tumors, may arise from any bone but tend to occur near the ends of long bones. ... Enchondroma. ... Chondroblastoma. ... Chondromyxofibroma. ... Osteoid osteoma. ... Nonossifying fibroma (fibrous cortical defect) ... Benign giant cell tumor of bone.

Drainage of a Submandibular Mouth Abscess

Rhinoplasty enhances facial harmony and the proportions of your nose. It can also correct impaired breathing caused by structural defects in the nose. Rhinoplasty surgery can change: Nose size in relation to facial balance Nose width at the bridge or in the size and position of the nostrils Nose profile with visible humps or depressions on the bridge Nasal tip that is enlarged or bulbous, drooping, upturned or hooked Nostrils that are large, wide, or upturned Nasal asymmetry If you desire a more symmetrical nose, keep in mind that everyone’s face is asymmetric to some degree. Results may not be completely symmetric, although the goal is to create facial balance and correct proportion.

New Hemorrhoids Treatment Method

The following guidelines are an interpretation of the evidence presented in the 2010 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations1). They apply primarily to newly born infants undergoing transition from intrauterine to extrauterine life, but the recommendations are also applicable to neonates who have completed perinatal transition and require resuscitation during the first few weeks to months following birth. Practitioners who resuscitate infants at birth or at any time during the initial hospital admission should consider following these guidelines. For the purposes of these guidelines, the terms newborn and neonate are intended to apply to any infant during the initial hospitalization. The term newly born is intended to apply specifically to an infant at the time of birth.