testNorepinephrine (INN) (abbreviated norepi or '''NE'''), also called ''''noradrenaline''' (BAN) (abbreviated NA, NAd, or norad), or 4,5-β-trihydroxy phenethylamine is a catecholamine with multiple roles including those as a hormone and a neurotransmitter. It is the hormone and neurotransmitter most responsible for vigilant [[concentration]] in contrast to its most chemically similar hormone, [[dopamine]], which is most responsible for cognitive alertness(? source needed) and working memory<ref>D1 dopamine receptors in prefrontal cortex: involvement in working memory, T Sawaguchi and PS Goldman-Rakic, Science 22 February 1991: 251 (4996), 947-950.</ref>. ==References==<references/>[[category:brain]]