Respiratory Sinus Arrhythmia (RSA) stress response in preschool age varies by serotonin transporter polymorphism...

Area of Science:

• Developmental Psychology
• Behavioral Genetics
• Neuroscience

Background:

• The serotonin transporter promoter region polymorphism (5-HTTLPR) is linked to stress regulation.
• Increased stress reactivity is often observed in carriers of the short (S) allele.
• The impact of 5-HTTLPR on parasympathetic stress reactivity, measured by Respiratory Sinus Arrhythmia (RSA), remains unclear.

Purpose of the Study:

• To investigate the association between 5-HTTLPR and RSA response to maternal separation in preschoolers.
• To examine individual differences in stress reactivity related to the 5-HTTLPR genotype.

Main Methods:

• A sample of 69 healthy 5-year-old children was genotyped for the 5-HTTLPR polymorphism.
• Respiratory Sinus Arrhythmia (RSA) was measured during an adapted Strange Situation Procedure (SSP).
• Multilevel models were used to analyze the dynamic RSA response to SSP episodes.

Main Results:

• A significant interaction was found between 5-HTTLPR genotype and SSP episodes.
• All children showed decreased RSA during the stranger episode.
• Short (S) allele carriers exhibited a distinct RSA pattern during separation, with an initial decrease followed by an increase.

Conclusions:

• The 5-HTTLPR genotype may contribute to individual variations in RSA stress reactivity.
• These findings suggest a potential role for 5-HTTLPR in early-developing parasympathetic regulation during stress.
• Further research is warranted to confirm these preliminary findings in preschool-aged children.