To obtain empirical evidence for the above clinical observations, we first confirmed the ME/CFS-like features under hyperserotonergic manipulation (extra- and intracellular hyperactivity of 5-HT) in the RN along with high 5-HTDRN→hypothalamus innervation (Fig. 2A–E). Here, HTR5A is linked to myalgic encephalomeyelitis/chronic fatigue syndrome.