Early experience and serotonin transporter gene variation interact to influence primate CNS function

Area of Science:

• Neuroscience
• Genetics
• Primate Research

Background:

• Nonhuman primates are valuable models for studying gene-environment interactions affecting physiology and behavior.
• Human studies link serotonin transporter gene (5-HTT) length variation (5-HTTLPR) to serotonergic function and psychopathology.
• Understanding these interactions is crucial for deciphering complex traits.

Purpose of the Study:

• To investigate the contributions of genotype and early environment to central nervous system (CNS) function in rhesus monkeys.
• To examine if an analogous variation in the monkey 5-HTTLPR gene interacts with early experience.
• To assess the impact on central serotonin (5-HT) functioning.

Main Methods:

• Analysis of a large sample of rhesus monkeys.
• Genotyping for the 5-HTTLPR gene region.
• Measurement of cerebrospinal fluid (CSF) concentrations of 5-hydroxyindoleacetic acid (5-HIAA), a 5-HT metabolite.
• Comparison between monkeys with varying early rearing experiences (deleterious vs. normal).

Main Results:

• A significant interaction between 5-HTTLPR genotype and early rearing environment was observed.
• Monkeys with adverse early experiences showed genotype-dependent differences in CSF 5-HIAA levels.
• Monkeys with normal rearing did not exhibit these genotype-dependent differences.
• This indicates an environment-dependent effect of the rh5-HTTLPR genotype on CNS 5-HT function.

Conclusions:

• The rhesus monkey 5-HTTLPR genotype influences CNS 5-HT function in an environment-dependent manner.
• Early life experiences modulate the impact of genetic variation on neurobiology.
• Nonhuman primates serve as a key model for investigating gene/environment interactions in candidate genes for behavioral and physiological traits.