Figure 8.

5-HTP-induced head twitches in WT mice are blocked by combined inhibition of N-methyltransferase and Akt. Pretreatment with the Akt inhibitor (AKTi) or the N-methyltransferase inhibitor (MTZ) individually reduce 5-HTP-induced twitches in WT mice; coadministration of the inhibitors is additive. Time course (A) and total numbers (B) of head twitches observed in WT mice after 10 min pretreatment with either vehicle (Veh; 0.1% DMSO in dH₂O, i.c.v.), AKTi (55 ng, i.c.v.), or MTZ (125 ng, i.c.v.) alone, or AKTi and MTZ concurrently before 5-HTP administration (200 mg/kg, i.p.) Vehicle versus inhibitor: ^##p < 0.01, ^###p < 0.001. AKTi versus AKTi + MTZ: **p < 0.01; MTZ versus AKTi + MTZ: ***p < 0.001. Mean ± SEM are shown.