Prefrontal Serotonergic Denervation Induces Increase in the Density of 5-HT sub(2A) Receptors in Adult Rat Prefrontal Cortex

• Published in: Neurochemical research 2008-11, Vol.33 (11), p.2350-2357
• Main Authors: Soria-Fregozo, Cesar, Perez-Vega, Maria Isabel, Gonzalez-Burgos, Ignacio, Feria-Velasco, Alfredo, Beas-Zarate, Carlos
• Format: Article
• Language: English
• ISSN: 0364-3190; 1573-6903
• DOI: 10.1007/s11064-008-9740-7

The 5-HTergic system and particularly 5-HT sub(2A) receptors have been involved in prefrontal cognitive functions, but the underlying mechanisms by which the serotonin (5-HT) system modulates these processes are still unclear. In this work, the effects of prefrontal 5-HTergic denervation on the density and expression levels of 5-HT sub(2A) receptors were evaluated by immunohistochemical and molecular biology studies in the prefrontal cortex (PFC). The [ super(3)H]-Ketanserin binding study revealed an increase in the B sub(max), along with no change in the binding affinity (K sub(D)) for 5-HT sub(2A) receptors. The increase in PFC of 5-HT sub(2A) receptor density in response to denervation was accompanied by increase in 5-HT sub(2A) receptor mRNA and protein levels. This increase in the number of 5-HT sub(2A) receptors may be interpreted as an adaptive plastic change, i.e., hypersensitivity; resulting from the selective pharmacological lesion of the raphe-proceeding 5-HTergic fibers to the PFC. Based on previous evidence, this could be strongly related to the abnormal expression of short-term memory.