Serotonin in the human striatum modulates social personality

Serotonin (5-HT) is a neurotransmitter that has been linked to a wide range of behaviours. Notably, 5-HT has been shown to regulate aggressiveness and affiliative behaviour. While 5-HT is classically considered to modulate social behaviour by acting on the so-called "social brain regions" such as the amygdala, insula and superior temporal sulcus, recent evidence indicates that 5-HT processes social reward via a context dependent modulation of the striatum. Additionally, the morphology and the functioning of the posterior putamen, a region of the dorsal striatum, have been correlated to social behaviour in both human and non human primates.

Because 5-HT1A receptors' response is linked to social behaviour and impact on grey matter morphology, we hypothesized that the amount of 5-HT1A receptor (assessed through Pet-scan) and grey matter volume (measured with MRI) would correlate in the putamen of healthy human subjects. Moreover, these measures should also be linked to social personality. Given the importance of 5-HT in Autism Spectrum Disorders (ASD) we have also investigated these associations in ASD patients.

In this April cortex student club, I will present the results obtained on 24 healthy subjects and 18 ASD patients.