Neurochemical substrates of ictal behavior.

Ictal activity is associated with (a) very marked changes in energy metabolism and neurotransmitter turnover and (b) complex secondary effects on second messenger systems and the control of protein synthesis. These events both reflect the abnormal patterns of excitatory and inhibitory activity and entail further modifications of neuronal function. More refined in vivo measurements of neurochemical changes and their anatomy will be required if we are to correlate the more subtle ictal behavioral abnormalities with their underlying events.