Figure 2. Gamma oscillations are blocked by tetrodotoxin (TTX), an AMPA/kainate receptor antagonist (DNQX), an AMPA receptor antagonist (GYKI) and a GABA_A receptor antagonist (GABAzine).

(A) Field potential recordings from a representative PrL slice shows oscillatory activity elicited by KA under control conditions and after application of TTX (500 nM). Traces show a large decrease in oscillations in the presence of TTX. The power spectral density (PSD) analysis of a 5 second epoch of field potential activity after KA application under both conditions (right), shows TTX significantly blocked elicited gamma activity. (B) Representative recordings of oscillatory activity elicited by KA before and after application of DNQX (5 µM). As shown by the PSD analysis (right), the kainate and AMPA receptor antagonist significantly blocked elicited gamma activity. (C) Representative recordings of oscillatory activity elicited by KA before and after application of GYKI 52466 (50 µM). As shown by the PSD analysis (right), the AMPA receptor antagonist significantly blocked elicited gamma activity. (D) Representative recordings of oscillatory activity elicited by KA before and after application of GABAzine. As shown by the PSD analysis (right), the GABA_A receptor antagonist blocked gamma oscillations. However, large amplitude epileptiform spiking activity was uncovered.