Tags: Anatomical Structure, Brain.
The median raphe nucleus (MRN) (also known as the nucleus raphes medianus (NRM) or superior central nucleus) is composed of polygonal fusiform and piriform neurons and exists rostral to the nucleus raphes pontis.Inhibition of the MRN in cats by lysergic acid diethylamide (LSD) and psilocin two serotonin agonist hallucinogens leads to dose dependent behavioral changes indicating the MRN may be an important site of action for humans hallucinations.