Serotonin, genetic variability, behaviour, and psychiatric disorders--a review

Area of Science:

• Neuroscience
• Psychiatry
• Developmental Biology

Background:

• Brain monoamines, particularly serotonin, are linked to psychiatric conditions like depression and anxiety.
• Genetic variations in MAOA and 5HTT genes are implicated, yet in vitro studies show increased serotonin, contradicting clinical observations of decreased levels.
• Observed discrepancies in adult humans and monkeys suggest early developmental events are key.

Purpose of the Study:

• To explore the hypothesis that early brain development, influenced by serotonin's dual role, impacts behavior and neuropsychiatric disorder risk.
• To investigate how serotonin's function as a neurotransmitter and neurotrophic factor during early development affects limbic neurocircuitry and serotonergic neuron development.

Main Methods:

• Review of recent research on serotonin's role in early brain development.
• Analysis of studies linking genetic polymorphisms to psychiatric conditions.
• Exploration of developmental pathways affected by serotonin.

Main Results:

• Serotonin's dual role as a neurotransmitter and neurotrophic factor significantly impacts early brain development.
• Altered development of limbic neurocircuitry and serotonergic neurons during early life is associated with behavioral and psychiatric risks.
• Contradictory findings regarding gene variants and serotonin levels may be explained by developmental effects.

Conclusions:

• The impact of serotonin on behavior and neuropsychiatric disorders is primarily mediated through its influence on early brain development.
• Understanding developmental processes is crucial for explaining the link between serotonin, genetics, and psychiatric conditions.
• Future research should focus on early developmental interventions and their long-term effects on mental health.