Aishwarya Belhe

Session 2
Board Number

Examining the Effects of Serotonin on Medium Spiny Neurons (MSNs)

Serotonin is the key hormone in stabilizing our mood and feelings of well-being. The relation between alterations in the levels of serotonin in the central nervous system and depression has been well-established. The most common antidepressants prescribed to alleviate the symptoms of depression are selective serotonin reuptake inhibitors (SSRIs), which increase the levels of serotonin in the brain. These drugs are also prescribed to pregnant women with chronic depression, although how the SSRI-induced increase in the level of serotonin affects fetal brain development has been minimally investigated. In this study, we investigated the effects of serotonin on the development of a particular type of neuron called medium spiny neurons (MSNs). These neurons are the major types of neurons present in the striatum, whose circuits have been implicated in depression. MSNs are known to have distinct morphological traits of cell body size, dendritic branching pattern and high density of dendritic spines. Although many studies have focused on the role of serotonin in regulating function of the mature striatum, no studies (that we can find) have specifically examined the role of serotonin on MSN development. Here we show that increase in serotonin results in an increase in dendritic branching of MSNs. These results indicate a need for caution about the consumption of SSRIs by pregnant women.