Physiological adaptations made by inhibitory synapses in the brain to counterbalance excessive excitatory activity. Possible consequences of an imbalance between excitatory and inhibitory synaptic activity are seizures and epilepsy. We are currently investigating the role of GABA metabolism in the dynamic regulation of inhibitory synaptic strength. Proteins we have showen to be involved in this regulation include a glutamate transporter and the GABA synaptic enzyme glutamic acid decarboxylase. Regulation of inhibitory synaptic transmission by these, and possibly other, proteins may serve to prevent hyperexcitability and seizures.