• Frontal cerebral cortex brain samples from schizophrenics and controls have been assayed for binding associated with muscarinic cholinergic, serotonin (5HT), γ-aminobutyric acid (GABA), and β-adrenergic receptors as well as for the activity of the GABA-synthesizing enzyme glutamic acid decarboxylase (GAD). Binding levels of tritium-LSD, presumably associated with postsynaptic 5HT receptors, were reduced 40% to 50% in samples from schizophrenics in three independent studies, whereas no other consistent alteration was observed in levels of binding associated with other receptors or in the activity of GAD. This change in receptor binding levels does not seem to be attributable to postmortem changes, to influences of drugs received by the patients, or to demographic features of the patient populations.
Bennett JP, Enna SJ, Bylund DB, Gillin JC, Wyatt RJ, Snyder SH. Neurotransmitter Receptors in Frontal Cortex of Schizophrenics. Arch Gen Psychiatry. 1979;36(9):927-934. doi:10.1001/archpsyc.1979.01780090013001