Compared to acute controls, NK1R binding was significantly reduced in SIDS cases in the NTS (p = 0.04), DAO (p = 0.01) and MAO (p = 0.03) ( Fig 3A ) and significantly reduced in the DAO (p = 0.01) and MAO (p = 0.03) with borderline significance in the PIO (p = 0.09) when compared to all controls combined (acute, chronic and hypoxic) ( Fig 3B ).
Analysis of [ 125 I] BH-SP binding to NK1R adjusted by sex Analysis of binding by sex revealed an overall trend for higher binding in male compared to female infants in both acute and combined control cohorts.
Analysis of [ 125 I] BH-SP binding to NK1R adjusted for age and prematurity status Fig 4 shows analysis of binding by PCA across diagnoses in select medullary nuclei and reveals a clear trend for binding to decrease with age in all nuclei displayed in non-SIDS controls, although a statistically significant reduction in binding was observed only in the ROb (acute controls p = 0.009, combined controls p = 0.04).
However despite the small sample size, we found highly significant differences (>50% higher in every nucleus analyzed) in NK1R binding in premature compared to term combined controls, compared to no significant differences observed in premature compared to term SIDS cases.