TNF and Alzheimer disease: We tested the role of this cytokine in middle-aged rats using etanercept, which is a decoy receptor for TNF-α.50 In middle-aged rats, co-injection of etanercept (50 μg in 5 μL, i.c.v.)52 significantly reduced the induction of LTD by LFS-300 in the presence of Alzheimer’s disease brain tau (Fig. 6A and B).