Fig 4. Changes of excitability of granule cells following treatment with Aβ and the protective effect of CCBs.
A, a small current injection was sufficient to evoke an AP in the control granule cells, but not in the EC-Aβ cells. B, the current required to evoke minimal AP firing in EC-Aβ granule cells (right panel) evoked strong AP firing in the control cells (left panel). C, the minimal current to evoke one AP during one second (rheobase current) is increased in the EC-Aβ granule cells compared to the control group. Treatment with calcium channel blockers, isradipine and nimodipine, preserved rheobase current in the EC-Aβ granule cells. D and E, the rheobase related to the Rin in the control and granule cells from Aβ treated rats, respectively. Note different y and x axis scales in these panels. Values are mean ± SEM. ***p < 0.001 compared to the control group and ##p < 0.01 compared to the EC-Aβ group. Control group, n = 15 cells/ 6 rats; EC-Aβ group, n = 15 cells/ 8 rats; EC-Aβ + ISR, n = 10 cells/ 6 rats; EC-Aβ + NIM, n = 7 cells/ 5 rats.