F-11,461 is a naphthylpiperazine drug that acts as an agonist of the 5-HT<sub>1A</sub> receptor (K<sub>i</sub> = 1.36 nM) that has been used as a radioligand in PET studies. It possesses modest affinity for the 5-HT<sub>7</sub> (K<sub>i</sub> = 9.1 nM) and D<sub>4</sub> (K<sub>i</sub> = 8.5 nM) receptors, although the interaction of F-11,461 with these receptors is not detectable with PET due to their relative scarcity in the brain.