Radix Ginseng and Semen Ziziphi Spinosae could affect the amount of GABA, GLN, GAD65, and GS and the expressions of mGluR5mRNA, NR1mRNA, and GluR1mRNA in the hippocampal tissue in rats induced by PCPA to insomnia through the GLU/GABA-GLN metabolic cycle. Here, GAD2 is linked to insomnia.