Serotonin 5-HT2A receptors are expressed on pyramidal cells and interneurons in the rat cortex

The distribution of 5‐HT2A receptors in rat cortex was evaluated using newly developed antibodies. Each of three antibodies tested identified an identical pattern of 5‐HT2A‐like immunoreactivity (5‐HT2A‐li) in rat cortex with 5‐HT2A‐li showing a widespread distribution. The majority of 5‐HT2A‐li cells displayed a pyramidal morphology. While a minority, some cortical neurons with a bipolar morphology displayed 5‐HT2A‐li as well. Dual‐label fluorescence confocal microscopic studies with a 5‐HT2A antibody and a mouse monoclonal antibody to parvalbumin, a marker of a subset of gamma aminobutyric acid (GABA)ergic interneurons in the cortex, demonstrated that although some cells expressing 5‐HT2A‐li were interneurons, most were not. Synapse 27:79–82, 1997. © 1997 Wiley‐Liss, Inc.