Animal models such as newborn piglet and Beagle puppy are widely used to study perinatal brain damages. However, there are no available data concerning normal metabolic evolution during brain development. Objective: To establish the profiles of metabolic changes during brain myelination for these two animal models. Methods: 4 beagle puppies and 20 piglets were followed from birth to 4 months and from birth to 1 month, respectively. Measurements were carried out on a Bruker MRS system operating at 2.35 Tesla. Absolute concentrations were determined with a new method: ERETIC (Electronic REference To assess In vivo Concentrations). This method used as a reference a synthesized signal which allowed the determination of absolute concentrations by comparison with the signal of the metabolites of interest. After sagittal imaging, the Volume Of Interest was placed on the thalamic region. Concentrations expressed in mmol/l accross brain maturation were fitted with monoexponential adjustments. Results: Absolute concentration of Choline (Cho) decreased whereas absolute concentration of both Creatine (Cre) and N-Acetyl-Aspartate (NAA) increased with brain maturation. Evolutions of the concentrations accross the studied periods expressed in% of the neonatal values are presented in table.

Table 1 No caption available.
Full size table

Conclusion: 1)Our study provides normative data suitable for follow-up studies after neonatal experimental insults for both preterm and full-term models. 2) ERETIC method is useful to study normal and delayed brain maturation in newborn infants.