The activities of glutamine synthesis in the brain extract of the rat treated with various methods, were observed by means of the Conway's microdiffusion analysis. The brain extract were incubated at 37℃, pH 7.2 for 25 minutes under aerobic condition. 1) The activity of glutamine synthesis in the rat' brain extract treated with intensive electro-shock series, averaged 2.21μM per tube and showed an increase in comparison with the control value. 2) In the insulin shock series it was 1.04μM per tube in average and was a lower level than the control value. 3) The activity averaged 0.91μM per tube in the Philopon (Pervitin) administration series. 4) In the Ritalin treatment series its average activity was 1.10μM per tube and so Philopon and Ritalin decreased in its comparative activities with the control.