Objectives: We used the PPA rodent model to investigate if there are any evidence for abnormal brain lipid metabolism associated with the occurrence of autistic-like behavioral changes following intraventricular infusions of phosphate buffer saline (PBS), propionic (PPA) and butyric acids (BUT).
Methods: Infusions (0.26M, 4µL animal-1) was done twice daily for 7 days after which animals were sacrificed and brains lipids analyzed using thin layer chromatography (TLC) and gas chromatography-mass spectrometry and flame ionization detection (GC-MS/FID).Brain phospholipids were separated into SM, CL, PS+PI, PC and PE following TLC analysis.
Results: Hydrolysis of the separated phospholipid components revealed significant quantitative changes in fatty acid components after treatments with PPA and BUT compared to the controls (PBS), with PPA generally more extensive than BUT in altering the lipid composition. PPA infusion resulted in decreased levels of total monounsaturates, total ω6 fatty acids and elevated levels of total saturates in all the separated phospholipid species. In addition, a decline in total plasmalogen PE and the ratio of ω6: ω3 was also present. Conversely, there was a consistent significant (P = 0.02) increase in total acylcarnitines, total long chain (C12 to C24) acylcarnitines, total short chain (C2 to C9) acylcarnitines, and the ratio of free to bound carnitine following infusions with PPA and BUT. Increases in the accumulation of the following acylcarnitines: C2:0, C14:1, C15:0, C16:0, C16:1, C18:0, C18:1, C22:0, C22:1 and C24:0 accounted for the increase levels of total acylcarnitines observed following infusions with PPA and BUT.
Conclusions: These results provide evidence of a relationship between changes in brain lipid profiles and the occurrence of behavioral changes associated with autism spectrum disorder using the autism rodent model.