Expression of Serotonin1A and Serotonin2A Receptors in Pyramidal and GABAergic Neurons of the Rat Prefrontal Cortex

• Published in: Cerebral cortex (New York, N.Y. 1991) N.Y. 1991), 2004-10, Vol.14 (10), p.1100-1109
• Main Authors: Santana, Noemí, Bortolozzi, Analía, Serrats, Jordi, Mengod, Guadalupe, Artigas, Francesc
• Format: Article
• Language: English
• Subjects: 5-HT1A receptors; 5-HT2A receptors; Animals; GABA interneurons; gamma-Aminobutyric Acid - metabolism; gamma-Aminobutyric Acid - physiology; Gene Expression Regulation; Male; medial prefrontal cortex; Neurons - chemistry; Neurons - metabolism; Prefrontal Cortex - chemistry; Prefrontal Cortex - metabolism; Pyramidal Cells - chemistry; Pyramidal Cells - metabolism; pyramidal neurons; Rats; Rats, Wistar; Receptor, Serotonin, 5-HT1A - biosynthesis; Receptor, Serotonin, 5-HT1A - physiology; Receptor, Serotonin, 5-HT2A - biosynthesis; Receptor, Serotonin, 5-HT2A - physiology
• ISSN: 1047-3211; 1460-2199; 1460-2199
• DOI: 10.1093/cercor/bhh070

Serotonergic 5-HT1A and 5-HT2A receptors are abundantly expressed in prefrontal cortex (PFC) and are targets of atypical antipsychotic drugs. They mediate, respectively, inhibitory and excitatory actions of 5-HT. The transcripts for both receptors are largely (∼80%) colocalized in rat and mouse PFC, yet their quantitative distribution in pyramidal and GABAergic interneurons is unknown. We used double in situ hybridization histochemistry to estimate the proportion of pyramidal and GABAergic neurons expressing these receptor transcripts in rat PFC. The number of GABAergic interneurons (expressing GAD mRNA) was a 22% of glutamatergic neurons (expressing vGluT1 mRNA, considered as putative pyramidal neurons). 5-HT2A receptor mRNA was present in a large percentage of pyramidal neurons (from 55% in prelimbic cortex to 88% in tenia tecta), except in layer VI, where it was localized only in 30% of those neurons. 5-HT2A receptor mRNA was present in ∼25% of GAD-containing cells except in layer VI (10%). Likewise, ∼60% of glutamatergic cells contained the 5-HT1A receptor transcript. We also found that ∼25% of GAD-expressing cells contained the 5-HT1A receptor mRNA. These data help to clarify the role of 5-HT in prefrontal circuits and shed new light to the cellular elements involved in the action of atypical antipsychotics.