News tagged with norepinephrine
Norepinephrine (INN) (abbreviated norepi or NE) is the US name for noradrenaline (BAN) (abbreviated NA or NAd), a catecholamine with multiple roles including as a hormone and a neurotransmitter. Areas of the body that produce or are affected by norepinephrine are described as noradrenergic.
The terms noradrenaline (from the Latin) and norepinephrine (derived from Greek) are interchangeable, with noradrenaline the common name in most parts of the world. However, to avoid confusion and achieve consistency medical authorities have promoted norepinephrine as the favoured nomenclature, and this is the term used throughout this article.
One of the most important functions of norepinephrine is its role as the neurotransmitter released from the sympathetic neurons affecting the heart. An increase in norepinephrine from the sympathetic nervous system increases the rate of contractions.
As a stress hormone, norepinephrine affects parts of the brain, such as the amygdala, where attention and responses are controlled. Along with epinephrine, norepinephrine also underlies the fight-or-flight response, directly increasing heart rate, triggering the release of glucose from energy stores, and increasing blood flow to skeletal muscle. It increases the brain's oxygen supply. Norepinephrine can also suppress neuroinflammation when released diffusely in the brain from the locus coeruleus.
When norepinephrine acts as a drug it increases blood pressure by increasing vascular tone (tension of muscles) through α-adrenergic receptor activation. The resulting increase in vascular resistance triggers a compensatory reflex that overcomes the direct homeostatic effect of that increase on the heart, called the baroreceptor reflex, which otherwise would result in a drop in heart rate called reflex bradycardia.
Norepinephrine is synthesized from dopamine by dopamine β-hydroxylase. It is released from the adrenal medulla into the blood as a hormone, and is also a neurotransmitter in the central nervous system and sympathetic nervous system where it is released from noradrenergic neurons in the locus coeruleus. The actions of norepinephrine are carried out via the binding to adrenergic receptors.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
Three studies released today present possible positive news for people with Parkinson's disease. The studies, which will be presented at the American Academy of Neurology's 65th Annual Meeting in San Diego, March 16 to 23, ...
Parkinson's & Movement disorders Mar 14, 2013 | 3.5 / 5 (2) | 0 |
(Medical Xpress)—What is the best intervention window for someone struggling with cocaine addiction? When he or she is in the middle of a drug binge, or after a period of abstinence when there is temptation ...
Psychology & Psychiatry Jan 15, 2013 | not rated yet | 0 |
(Medical Xpress) -- University of Kansas researchers have found larger resting pupil size and lower levels of a salivary enzyme associated with the neurotransmitter norepinephrine in children with autism spectrum ...
Autism spectrum disorders Jul 13, 2012 | 5 / 5 (3) | 0 |
(Medical Xpress) -- Because addictions cause so much havoc in the lives of millions of people, researchers the world over are constantly looking for both their causes and ways to treat them. One such addiction, to gambling, ...
Psychology & Psychiatry Feb 22, 2012 | 5 / 5 (1) | 0 |
Stressed people fall into habits and their behaviour is not goal-directed. That the neurotransmitter norepinephrine plays a decisive role here is now reported in the Journal of Neuroscience by scientists from Bochum led by ...
Neuroscience Nov 28, 2011 | not rated yet | 1 |
Novel imaging could better identify patients who would benefit from implantable cardiac defibrillator
New research from the University at Buffalo suggests that cardiologists may have a new way to identify patients who are at the highest risk of sudden cardiac arrest, and the most likely to benefit from receiving an implantable ...
Cardiology May 10, 2012 | not rated yet | 0
It's a common belief that there's a link between chronic stress and an increased risk of cancer. In new research published online by the International Journal of Cancer, scientists at The University of Western Ontario have t ...
Cancer Sep 20, 2011 | not rated yet | 0