(±)-Methylserotonin maleate salt is a salt of -Methylserotonin maleate and is a serotonin (5-HT) receptor agonist with preference for 5-HTA, 5-HTB, 5-HTC receptors. This agonist has been utilized in studies of aggression involving the central amygdaloid nucleus in female Wistar rats. Additional studies with frog spinal cord motoneurons in the presence of NMDA receptor open-channel blockers and high concentrations of α-methy-5-hydroxytryptamine indicated that these high concentrations significantly potentiated NMDA-induced depolarizations in these motoneurons.