Abstract:  Maternal behavior is a complex social behavior which is essential for the survival and development of the offspring. Many progresses have been made in recent decades on the neurobiological mechanisms of maternal behavior, especially in rodents. The present study focuses on the serotonin system, a major neurotransmitter system that has not received enough attention in this field. We first provide a brief overview of rat maternal behavior and the basic functions of the serotonin system. Next, we review recent work on the role of serotonin in the mediation of maternal behavior, focusing on the specific receptor subtypes. We examine evidence concerning the physio-psychological and neuroanatomical, neurochemical and neuroendocrine mechanisms of serotonin and the related gene regulation. Finally, we point out several future research directions, one of which concerns the potential interactions between serotonin and other neurochemicals, such as dopamine and oxytocin in the regulation of maternal behavior.

Key words: serotonergic system, maternal behavior, neuronal circuit, hormone