^^^yes, it is the major receptor mediating the psychedelic effects of serotonergic hallucinogens. However, a single type of G-protein coupled receptor can couple to multiple downstream effectors, and the effectors to which it couples are dependent on how it is activated by an agonist. Different agonists will cause distinct conformational changes in the receptor, and thereby traffic the receptor stimulus selectively to certain signaling pathways. Is that clear or should I break it down a little more? I believe Bilz0r wrote a more extended treatment of this topic in the Erowid/Bluelight guide to neuropharmacology.