Figure 8.

Blocking of αCaMKII activity in early and late phases. Simulations are implemented with and without a (Ca²⁺)₄–CaM pulse. Solid line indicates the αCaMKII concentration without any pulse stimulus, whereas dotted line indicates the αCaMKII concentration with pulse stimulus (pulse stimulus is used to mimic the effect of HFS). (A) αCaMKII activity blocking during induction for 5 min (solid thick black line shows blocking time). For different levels of αCaMKII activity blocking, L-LTP has different outcomes during the maintenance phase. (B) αCaMKII activity inhibition during maintenance for 900 min (solid thick black line shows blocking time). For very high levels of αCaMKII activity blocking, the upregulated state can still be maintained, suggesting that, with a very high-level inhibition of αCaMKII activity, the L-LTP expression can still be observed, and a complete reversal of L-LTP in the maintenance phase requires a very high dose and sustained application of the αCaMKII activity inhibitor.