Fewer 5HT2a (serotonin) receptors in pcc & acc in autistics


The posterior cingulate cortex (PCC) is activated when normal subjects see faces or hear voices of emotionally significant people in their lives; however, in autism the level of activation is impaired. [...]

The use of selective serotonin reuptake inhibitor (SSRI) medication has been shown to be successful in the treatment of autistic behaviors in some individuals. Serotonin (5-HT) has a role in neuronal development and has been extensively studied in autism with reports of excess 5-HT in the blood (hyperserotonemia) in some people with autism. [...]

The results show that there was a significant decrease in the density of one key type of serotonin receptor, the 5HT2A receptor, in the superficial cortical layers of the PCC in the adult autistic group when compared to age-matched controls. Similar results were found recently in the anterior cingulate cortex, an area involved in social-emotional processing. Evaluated together, these findings suggest that the 5-HT2a serotonin receptor decrease occurs in widespread cortical areas and may play a central role in some of the social deficits observed in autism. (via.)