Table 3.

The important metabolic pathways engaged in neuronal differentiation and the involvement of the differential metabolites in the PLLA AF and RF groups

No.	Important metabolic pathways for neuronal differentiation	PLLA AF			PLLA RF
		12h	24h	36h	12h	24h	36h
1	Phenylalanine, tyrosine and tryptophan biosynthesis	√	√	√	√	√	√
2	Phenylalanine metabolism	√	√	√	√	√	√
3	Histidine metabolism	√	√	√	√	√	√
4	Aminoacyl-tRNA biosynthesis	√	√	√	√	√	√
5	Alanine, aspartate and glutamate metabolism	√	√	–	–	√	√
6	d-glutamine and d-glutamate metabolism	√	√	–	–	√	√
7	Taurine and hypotaurine metabolism	√	√	√	–	–	–
8	Arachidonic acid metabolism	√	√	√	–	–	–
9	Tyrosine metabolism		√	–	–	–	–
10	Glycine, serine and threonine metabolism	–	–	–	–	√	–

√ represents the involvement of the differential metabolites; - represents the noninvolvement.