norepinephrine

Examples of norepinephrine in the following topics:

• Stimulants

  • Some stimulants facilitate the activity of certain neurotransmitters, specifically norepinephrine and/or dopamine.
  • Amphetamines (such as ephedrine and methamphetamine) are a group of stimulants that increase the levels of norepinephrine and dopamine in the brain through reuptake inhibition—meaning they block these neurotransmitters from being reabsorbed back into the neural networks.
  • MDMA differs from most stimulants in that its primary pharmacological effect is on the neurotransmitter serotonin rather than dopamine, epinephrine, or norepinephrine.
  • Norepinephrine and dopamine reuptake inhibitors (NDRIs) (such as the antidepressant Wellbutrin) inhibit the uptake of dopamine and norepinephrine, effectively increasing their amounts in the brain and causing a stimulating effect.

• How the Body Responds to Stress

  • The hormones epinephrine (also known as adrenaline) and norepinephrine (also known as noradrenaline) are released by the adrenal medulla.
  • Epinephrine and norepinephrine increase blood glucose levels by stimulating the liver and skeletal muscles to break down glycogen, and by stimulating glucose release by liver cells.
  • Epinephrine and norepinephrine are collectively called catecholamines.
  • Studies in mice and human cancer cells grown in a laboratory have found that the stress hormone norepinephrine may promote angiogenesis and metastasis.

• Pharmacotherapy (Medication)

  • The most commonly used antidepressants primarily affect the norepinephrine and serotonin (monoamine) neurotransmitter systems.
  • Most antidepressants increase the available amount of norepinephrine or serotonin (or sometimes both) at the neuronal synapse, by decreasing the reuptake of these neurotransmitters into the pre-synaptic cell.
  • They do this by inhibiting the norepinephrine transporter or the serotonin transporter, or by decreasing the metabolism of these neurotransmitters.

• The Endocrine System and Stress

  • This causes a negative feedback cycle in which the steroids inhibit the hypothalamus and the pituitary gland, and it also causes the adrenal gland to produce the hormones epinephrine (also known as adrenaline) and norepinephrine.

• Specific Effects of Stress: Cancer

  • Studies in mice and human cancer cells grown in a laboratory have found that the stress hormone norepinephrine, part of the body's fight-or-flight response system, may promote angiogenesis and metastasis.

• Panic Disorder and Panic Attacks

  • Located in the brainstem, the locus coeruleus is the brain’s major source of norepinephrine, a neurotransmitter that triggers the body’s fight-or-flight response.
  • Such findings have led to the theory that panic disorder may be caused by abnormal norepinephrine activity in the locus coeruleus (Bremner, Krystal, Southwick, & Charney, 1996).

• Bipolar Disorders

  • People with bipolar disorders often have imbalances in certain neurotransmitters, particularly norepinephrine and serotonin (Thase, 2009).
  • Medications that are used to treat bipolar disorders (such as lithium) work to block norepinephrine activity at the synapses.

• Substance-Related and Addictive Disorders

  • It has been seen that some pathological gamblers have lower levels of norepinephrine than normal gamblers.
  • According to a study conducted by Alec Roy, formerly at the National Institute on Alcohol Abuse and Alcoholism, norepinephrine is secreted under stress, arousal, or thrill, so pathological gamblers gamble to make up for their under-dosage.

• Social Anxiety Disorder (Social Phobia)

  • Prescribed medications include several classes of antidepressants: selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and monoamine oxidase inhibitors (MAOIs).