Fig. 2.

Old male FBN rats demonstrated many features of cognitive decline and increased markers of neuroinflammation. In old rats, a body weight, b lean mass, and c fat mass were significantly greater than in young rats (n = 10 per group). d Preference for novel object placement in the object placement (OP) test in young (n = 13) and old (n = 11) rats. At a discrimination threshold of 55%, significantly fewer old rats relative to young rats preferred the novel object. f–g Old rats exhibited deficits in acoustic startle response, with significant decrements in prepulse inhibition (PPI, as determined by %PPI Max), twofold increased startle latency (defined as the time to the onset of the startle response, T Onset mean), and reduced displacement of a piezoelectric platform in response to an auditory stimulus at three volumes (90, 100, and 115 dB; p ≤ 0.001). h–i RT-qPCR was performed to assess age-related changes in expression of selected genes in cerebral cortex and hippocampus in Young (n = 13) and old (n = 14) rats. Young versus old comparisons were conducted using an independent sample t-test while OP preference (d) was analyzed via the chi-square test. Bar and line graphs represent mean ± SE. Expression was normalized to that of Actb and quantified as fold-change in old relative to young using the ΔΔCt method. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001