Meghan Puglia | Epigenetic regulation of brain signal complexity in infancy

Oxytocin is a naturally occurring neuromodulator known to regulate social behavior and brain signaling. Individual differences in the endogenous oxytocinergic system are due in part to epigenetic variability of the oxytocin receptor gene (OXTR) through DNA methylation. We have previously identified a region of OXTR in which increased methylation is associated with decreased levels of transcription in human cortex. Therefore, those with low OXTR methylation likely have increased access to endogenous oxytocin. We hypothesized that early-life differences in the oxytocinergic system drive differences in neural complexity during social perception. Measures of neural complexity capture the inherently fluctuating nature of the brain and are positively associated with cognitive development and behavioral performance.

To test the hypothesis that infants with greater access to endogenous oxytocin will show greater neural complexity to social stimuli, we assayed OXTR methylation from 101 infants at 5 months of age. At 8 months of age, we presented the same infants with social auditory stimuli while undergoing EEG, and collected measures of infant social behavior. Neural complexity was quantified as the area under the multiscale entropy curve. We find that infants with decreased OXTR methylation at 5 months of age show significantly increased neural complexity in response to social stimuli at 8 months of age. Infants with increased neural complexity also show significantly increased approach behavior. These results suggest that the oxytocinergic system may regulate social behavior by establishing unique neural patterns to social stimuli early in life.

Poster