Importantly, although phospholipase C (PLC) γ and phosphatidylinositol 3-kinase (PI3K) have also been implicated in BDNF signaling, their activation is not required for spatial long term memory recovery in AD model rats because neither PLCγ inhibitor U-73122 nor PI3K inhibitor wortmannin blocks the beneficial effect of hippocampal BDNF on long term memory restore in the Aβ1-42-injected rats (data not shown). Here, BDNF is linked to Alzheimer disease.