Lsamp-/- mice display lower sensitivity to amphetamine and have elevated 5-HT turnover

► Lsamp-/- mice have lower sensitivity to amphetamine. ► Lsamp-/- mice have lower serotonin (5-HT) level, but greater 5-HT turnover rate. ► Amphetamine increases the level of 5-HT to a greater extent in Lsamp-/- mice. ► Amphetamine lowers 5-HT turnover to a greater extent in Lsamp-/- mice. ► Lsamp-/- mice have less dopamine transporter mRNA in the mesencephalon.