In contrast, in PD low visual performers SC–FC decoupling was more prominent in regions with increased serotoninergic receptor expression, specifically HTR1E and HTR5A. Although the function of these receptors is not yet fully described, HTR5A is thought to have a role in cognition65, with 5HT-5a antagonists improving cognition in animal models66. The gene discussed is HTR5A; the disease is Parkinson disease.