While ictaform activity is a hallmark of temporal lobe epilepsy, most studies in slices of the temporal lobe obtained from epilepsy surgery have failed to demonstrate spontaneous bioelectrical activity. In the present study, the activity of the human lateral amygdala (LA; n=18) was monitored using electrophysiological and optical (RH 795) multiple site recording techniques. Here, sharp waves appeared spontaneously in groups or continuously throughout the recordings. Their frequency ranged between 0.1 and 10 waves/sec. Potentials were monophasic, biphasic or triphasic in nature. Differences in the degree of spatio-temporal synchronization were observed between recording sites, and activity propagated preferentially along a latero-medial axis in the LA. All potentials were reversibly blocked by CNQX (10 mM), whereas APV (50 mM) had no effect. Bicuculline (10 mM) induced a suppression of spontaneous activity upon application and excessive rebound effect upon wash-out. Therefore, non-NMDA type glutamatergic and GABAergic synaptic transmission contribute to increased neural synchronization in the LA.