The study of how psychoactive drugs interact with the brain is called
psychopharmacology. More is said about nicotine in Chapter 9; I’ll say
more about atropine now.
Atropine receives its name from one of the plants in which it is
found, Atropa belladonna, the deadly nightshade (Fig. 8.3). Atropa bel-
ladonna has long been known as a highly poisonous plant, used for its
deadly effects to poison enemies and, in lower doses, for its medicinal
effects. Atropine was first isolated from Atropa belladonna around
- Being an antagonist at mAChRs, it is a parasympatholytic. As
such, it will slow intestinal motility, making it useful as a medicine to
treat diarrhea, spastic colon, and other kinds of gastrointestinal prob-
lems. Historically, it has also been used to dilate the pupil of the eye,
although in contemporary ophthalmology its use has been replaced
with shorter-acting mAChR antagonists.
The Latin genus for the plant comes from one of the goddess sisters
of Greek myth called the Moirai (plural of Greek moira = share, ap-
portion, fate). These sisters are Clotho, who spins the thread of life;
Lachesis, who measures out the thread of life; and Atropos, who cuts
the thread of life. In English they are called the Fates. Clearly the genus
name Atropa refers to the poisonous aspects of the plant. The Latin
species name, belladonna, literally means beautiful (bella) woman
(donna). This is in reference to the pupil dilation effect of the plant.
Other things being equal, folks will often judge a person having larger
pupils as more attractive. Ladies of yore used extracts of Atropa bel-
ladonna to dilate their pupils, enhancing their beauty.