Does [3]serotonin label presynaptic receptors in rat frontal cortex?

Several investigators have shown the presence of two types of central nervous system receptors for serotonin but the functional significance of these receptors is unknown. Using a 5,7-dihydroxytryptamine lesion and a direct binding assay, we have investigated the suggestion that one of these sites may occur presynaptically in rat cortex and possibly function as an autoreceptor. Our results disprove this theory and furthermore, they show that cortical serotonin receptors do not exhibit denervation supersensitivity.