HIGHS AND LOWS

THE power of psychoactive drugs may vary during the female menstrual
cycle, researchers in Italy have found. Although women consume more
than two thirds of drugs prescribed for depression and anxiety, almost
all drugs are tested only on men and male animals.

Paola Palanza and Laura Gioiosa at the University of Parma gave female
mice two types of anti-anxiety drugs, each of which affects different
neurotransmitters. Benzodiazepines increase the inhibitory effect of
gamma-aminobutyric acid (GABA), while buspirone binds to serotonin
receptors. Mice in oestrus needed only a small dose of buspirone.
During other parts of the cycle, however, the mice needed five times
as much buspirone to calm them, the researchers told a meeting on
animal behaviour in Urbino, Italy, last week. The animals were also
more sensitive to benzodiazepines during oestrus.

"In a lot of scientific fields, females have been neglected as subjects,"
says Palanza, adding that more attention should be paid to the interaction
between the female hormones and the serotonin and GABA systems in the
brain.

Checked-by: Rich O'Grady