Perampanel Inhibition of AMPA Receptor Currents in Cultured Hippocampal Neurons
(A) Sample currents evoked by 100 µM AMPA in 4 neurons in the absence (left panels) and presence (right panels) of perampanel at the concentrations indicated demonstrating a concentration-dependent reduction in current. (B) Perampanel (1 µM) did not alter the mean values of the ratio of the peak to the late amplitude of currents evoked by 10, 30 and 100 µM AMPA in 7, 8 and 7 neurons, respectively, and (C) did not affect the mean rise time constant values or mean decay time constant values of the currents. Peak (D) and late (E) current values evoked by various AMPA concentrations expressed as percent of control prior to perampanel. Curves represent logistic fits to the data for each AMPA concentration. Peak current is the maximum current level; late current is the current during the last 100 ms of the perfusion. Data points in D and E represent mean ± S.E.M. of values from 3 to 9 neurons. Control values for peak/late ratio: 10 µM AMPA: 1.5±0.1; 30 µM AMPA: 1.7±0.1; 100 µM AMPA: 2.7±0.3. Control values for decay time constant (ms): 10 µM AMPA: 141±13; 30 µM AMPA: 93±7; 100 µM AMPA: 50±2. Control values for rise time (ms): 10 µM AMPA: 51±2; 30 µM AMPA: 45±3; 100 µM AMPA: 32±1.