Noradrenaline

Noradrenaline is an example of a Neurotransmitter and also a Hormone. It is also known by the name Norepinephrine. This catecholamine is mostly responsible for concentration, and are released in response to physical or mental stress. This hormone affects many parts of the brain. The hormone affects adrenergic receptors, which are transmembrane proteins spanning across the plasma membrane of many cell types.

 

 References

1. 'The Adrenal Glands',  http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/A/Adrenals.html, accessed 21.10.2013