Fig. 2

Boosting hippocampal Fndc5/irisin alleviate hippocampal damage and cognitive deficits following experimental VaD. A Experimental outline. Forced expression of Fndc5 in hippocampus of adult C57BL/6 mice using adenovirus brain infection, while enhancement of hippocampal irisin level by bilateral intrahippocampal injection of recombinant irisin on day 22 after BCAS. B Hippocampal Fndc5 mRNA expression and irisin were respectively detected using qPCR and ELISA on day 28 after BCAS. C Hippocampal synaptic plasticity was analyzed using Patch Clamp on day 28 after BCAS. The average traces of fEPSP in hippocampal slices. D The data of fEPSP at 120 min. E–G Cognitive evaluation were performed on day 28 after BCAS. The errors (numbers of entries into incorrect maze arms) in two-days radial arm water maze test were continuously measured in each block (E). The errors in last block were counted in a histogram (F). Exploratory time on old or new object in novel object recognition test were illustrated in histogram (G). H, I Hippocampal level of TGF-β and IL-10, were determined using ELISA on day 28 after BCAS. J The percentage of freezing time obtained on day 28 after BCAS in contextual fear test were illustrated in histogram. Sham, sham-operated mice; BCAS, mice were subjected to BCAS injury; AdFndc5 or AdGFP, adult BCAS mice were infected using intracerebroventricular injection with an adenoviral vector designed to express Fndc5 or GFP; Irisin, adult BCAS mice with bilateral intrahippocampal injection of recombinant irisin. (n = 8 per group. All data are expressed as mean ± SEM, *P < 0.05, **P < 0.01, ***P < 0.001, ns means no statistical significance)