GABA depletion in chick brain-stem after intraventricular injection of cefazolin.

The effects of cefazolin, given into the III cerebral ventricle at different doses were studied on GABA content, GAD and GABA-T in the brain-stem of young chickens (Gallus domesticus). A dose-dependent fall in GABA content was observed; GABA decrease was evident 15 min after the administration, reached its nadir at 60 min and disappeared at 120 minutes. Glutamate decarboxylase and GABA-transaminase activity were not significantly changed. Present experiments suggest the excitatory and convulsant effects of cefazolin in chicks are related to GABA depletion in the brain-stem.