Figure 6.
Aging reduces long 3′ UTR BDNF transcripts in CA1 and CA3; and impairs fear-conditioning-induced expression of long 3′ UTR BDNF transcripts. (A) Basal expression in CA1 was severely reduced by both age (F1,42 = 74.1, p < .001) and infection (F1,42 = 47.1, p < .001); infection altered levels in young animals, and further reduced expression in aged animals. Fear conditioning elicited robust increases in expression in CA1 of young animals and aged/vehicle animals, but a more modest increase in CA1 of aged/infected animals (F1,42 = 63.6, p < .001). (B) In CA3, age reduced expression (F1,45 = 155.5, p < .001), but infection did not. There was no effect of fear conditioning. (C) Neither age or infection significantly altered levels in DG. There was no effect of fear conditioning. (D–G) Representative in situ hybridization images of basal expression of long 3′ UTR BDNF transcripts in hippocampi of (D) young vehicle, (E) young infected, (F) aged vehicle, and (G) aged infected animals. N = 6–8 animals/group. Error bars indicate SEM. *p < .001, age; **p < .001, infection; ***p < .001, fear conditioning.