Figure 3.

5-HT6 receptor ligand-mediated cAMP formation in stably transfected HEK-293F/rat 5-HT6 cells in either the absence or copresence of forskolin. HEK-293F cells were stably transfected with rat 5-HT6 receptor as described in Methods. cAMP formation was determined after a 2 h serum-free incubation in the presence of indicated ligands in either the absence (a) or presence (b) of 1 μM forskolin using FlashPlate technology. Mean dose–response curves±s.e.m. are shown from five to six independent experiments performed in duplicate. Mean E_max and pEC₅₀ values±s.e.m. are summarized in Table 2.