Figure 4

Kinetics of K⁺ flux in response to acute application of 10 μM glutamate. K⁺ flux was measured from age-similar control cells (A) and primary cortical neurons treated daily with 1 μM Aβ_1-40 for six days (B). Flux values were recorded for 5 min before glutamate application (-5 to 0 min) and 25 min afterwards with data acquired at a rate of 10 samples/sec and averaged over every 6 sec. Glutamate (10 μM) was applied at zero time as indicated by an arrow and led to a transient K⁺ efflux from neurons that returned to pre-stress conditions within 15 min afterwards. Notably, the magnitude of K⁺ efflux was higher in Aβ treated cells as shown by comparison of the peak values. Negative values of K⁺ flux indicate "efflux". Shaded area in panel B indicates total K⁺ efflux over 20 min after glutamate treatment. One (out of 7) typical example is shown.