The ratio of 1/3 linoleic acid to alpha linolenic acid is optimal for oligodendrogenesis of embryonic neural stem cells

•In this study, we investigated the effect of various concentrations and ratios of linoleic acid (LA) and alpha linolenic acid (ALA), which belong respectively to ω-6 and ω-3 PUFAs, on the proliferation and differentiation of eNSCs.•Low or high concentrations of ALA, but not LA, and the ratio of 1:3 of LA/ALA significantly increased neurospheres size, frequency and cell numbers, in comparison to controls, but also increased the mRNA expression levels of Notch-1, Hes-1 and Ki-67.•Low or high concentrations of ALA, but not LA had a significant increase on the differentiation of eNSCs toward astrocytes (GFAP) and oligodendrocytes (MBP), but not neurons (β-III Tubulin), in comparison to controls.•This study demonstrates the importance of higher concentrations of ALA relative to LA. During neural development, embryonic neural stem cells (eNSCs) differentiate toward glial, oligodendrocytic, and neuronal cells. Dysregulation of polyunsaturated fatty acids (PUFAs) induce a wide range of neurological and developmental disorders. In this study, we investigated the effect of various concentrations and ratios of linoleic acid (LA) and alpha linolenic acid (ALA), which belong respectively to omega-6 and omega-3 PUFAs, on the proliferation and differentiation of eNSCs.Results showed that low (25 and 50μM) or high (100 and 200μM) concentrations of ALA, but not LA, and the ratio of 1:3 of LA/ALA significantly increased neurospheres size, frequency and cell numbers, in comparison to controls. Moreover, low or high concentrations of ALA, but not LA, and different ratios of LA/ALA resulted in a significant increase in mRNA expression levels of Notch1, Hes1 and Ki-67, and the differentiation of eNSCs toward astrocytes (GFAP) and oligodendrocytes (MBP), but not neurons (β-III Tubulin), with the highest increase being for LA/ALA ratio of 1:3, in comparison to controls. These results demonstrate the importance of higher concentrations of ALA in enhancing proliferation and differentiation of eNSCs, which could be used in diet to help preventing neurodevelopmental syndromes, cognitive decline during aging, and various psychiatric disorders.