Glu of cns mainly comes from glutamine and phosphate activated glutaminase ( pag ) can decomposed the glutamine to glu and ammonia and is the main source of the glu of the cns , so pag is used as the special marker of glutaminergic neurons 磷酸激活的谷氨酞胺酶（ pag ）能催化谷氨酞胺水解为giu和氨，是中枢内gill的主要来源。困此pag一直被作为研究gill能神经元的特异性标识物。
