Cortical excitability reflects a balance between excitation and inhibition. Glutamate is the main excitatory and GABA the main inhibitory neurotransmitter in the mammalian cortex. Changes in glutamate and GABA metabolism may play important roles in the control of cortical excitability. Glutamate is the metabolic precursor of GABA, which can be recycled through the tricarboxylic acid cycle to sy...

Silver-intensified gold (SIG) particles were used for lightand electron-microscopic immunocytochemical localization of neuronal antigens, and the SIG method was compared with related heavy-metal methods for the purpose of dual ultrastructural localization of neurotransmitter-related antigens. SIG immunostaining was combined with peroxidase immunostaining to allow simultaneous study of different...