(B) Quantification of the number of population spikes in WT and PrP-null slices in aCSF. (C, top) Minimum stimulus intensity required to evoke a single population spike in WT and PrP-null slices. (middle) Stimulus intensity required to evoke maximum single population spike amplitude. (bottom) Extent of paired pulse facilitation in WT and PrP-null slices. (D, top) Field potentials recorded from PrP-null slices before and after the application of 50 μM APV as shown for P2. (bottom) Quantification of the number of population spikes before and after APV application in PrP-null slices. (E) Evoked field potentials recorded after 5 min of perfusion in zero-magnesium aCSF (ZM-aCSF). The gray arrows indicate successive population spikes, which are augmented in the PrP-null slices. (F, left) The number of population spikes overriding the fEPSP in slices exposed to ZM-aCSF. (second graph) Time to the observance of the first seizurelike discharge in ZM-aCSF. (third graph) Time to the occurrence of the first seizurelike event (SLE) upon perfusion with ZM-aCSF. (right) Duration of seizurelike events in WT and PrP-null slices. The black and gray arrowheads indicate the primary population spikes and the additional population spikes, respectively, overriding the fEPSP in each pulse (P1 and P2); these latter polyspikes were only observed in PrP-null mice. Data are represented as mean ± SEM (error bars) with statistical significance denoted as *, P < 0.05 and **, P < 0.001. Numbers in parentheses indicate the number of slices.<p><b>Copyright information:</b></p><p>Taken from "Prion protein attenuates excitotoxicity by inhibiting NMDA receptors"</p><p></p><p>The Journal of Cell Biology 2008;181(3):551-565.</p><p>Published online 5 May 2008</p><p>PMCID:PMC2364707.</p><p></p