you're now at: MAIN :: Neurotransmitters I :: Norepinephrine
Abbreviation: NE
Alias: Noradrenaline
Drug targets involved: NERT (reuptake pump), Alpha and beta-adrenergic receptors, Monoamine Oxidase (MAO; breakdown enzyme)
Notoriety: Perhaps the most underappreciated of the neurotransmitters (vying with acetylcholine). Until the advent of SSRIs, virtually all antidepressants involved action on NE. Controls a lot of "autonomic" (involuntary) nervous system functions, such as blood pressure.
Trivia: Most NE (along with serotonin and dopamine) is located in the gut, and has nothing to directly do with our brains. Also, most NE receptors are also associated with the familiar chemical adrenaline (so it's no surprise that NE is also called NORadrenaline!).
A gravely (if you ask me) underappreciated neurotransmitter is our friend norepinephrine (also known as "noradrenaline" and abbreviated as "NE"; I'll be using the abbreviation mostly as I'm too lazy to type out "norepinephrine" all the time). Related chemically to dopamine, and to a lesser extent, serotonin, it has effects in the central and peripheral nervous systems.
The first two major classes of antidepressants, the MAOIs (Monoamine Oxidase Inhibitors), and TCAs (Tricyclic Antidepressants) involved enhancing transmission via NE. MAOIs would slow the breakdown of NE (along with serotonin and dopamine) within neurons, and the TCAs had actions of inhibiting norepinephrine (along with serotonin) reuptake, causing norepinephrinergic synapses to flood with the stuff. The "atypical" antidepressants (AADs) also involved NE, and the AAD LUDIOMIL (maprotiline) involved solely norepinephrine as its target.
During the SSRI "revolution" (SSRIs include drugs such as fluoxetine/PROZAC), norepinephrine was dropped as a molecule of importance in depression. It looks like we've regained interest in NE, as the newest generation of antidepressants, the SSNRIs (Selective Serotonin and Norepinephrine Reputake Inhibitors, including drugs such as EFFEXOR/venlafaxine and CYMBALTA/duloxetine) also enhances NE transmission by flooding synapses with NE as well as serotonin. SSNRIs may sound real similar to the TCAs, but there are differences in specific action(s) and side effects (more on that later).
This page last updated 15 May 2008.
