Summary: This agent, M100,907 has been characterized as
a 5HT2A receptor antagonist. We have found it
to work in low dosage in an animal model of
psychosis that can be induced by lowering glu-
tamatergic function (3739). Recently this com-
pound has also been found to possess antipsy-
chotic properties in schizophrenic patients (40).
These and other observations support the view
that in addition to dopamine, glutamate and se-
rotonin are also critically involved in schizophre-
nia. It is likely that other neurotransmitters, such
as noradrenaline, acetylcholine, and -aminobu-
tyric acid (GABA), will soon be added to this
1. A. Carlsson, P. A. Shore, B. B. Brodie, J. Pharmacol.
Exp. Ther. 120, 334 (1957).
2. A. Carlsson, N.-Ć. Hillarp, Kungl. Fysiogr. Sašllsk. Lund
fošrhandl. 26, 1 (1956).
3. Ć. Bertler, A. Carlsson, E. Rosengren, Naturvissen-