Fig. 1

MS rats exhibit age-related impairments in sensorimotor gating and cognitive behaviors at PND65. A Experimental protocol. Litters were subjected to MS during lactation on PND9. Behavioral tests were performed during PND31-40 and PND56-65. Rats received BrdU injections intraperitoneally on PND35 and NAM from PND35 to PND65. PND, post-natal day; MS, maternal separation; BrdU, 5-bromo-2'-deoxyuridine. B The baseline startle response to an auditory-evoked startle stimulus of 120 dB is shown in the left panel. Percentage PPI of the auditory startle reflex for different pre-pulse intensities on PND40 in the right panel. C The baseline startle response to an auditory-evoked startle stimulus of 120 dB is shown in the left panel. Percentage PPI of the auditory startle reflex across different pre-pulse intensities on PND65 in the right panel. D Schematic of the novel object recognition experiment. E, F On day 2, time was spent exploring the two identical sample objects within the 10-min period. On day 3, time was spent exploring novel and old objects during the 10-min period on PND40 and PND65. G Trajectory graphs providing examples of the route taken to explore the target location by all groups in the Barnes maze test. The red and blue dots represent the start and end positions, respectively. The green line represents the trajectory. The target hole is labeled with a black circle. H The latency to the target hole in the Barnes maze test at PND40. I The latency to the target hole in the Barnes maze test at PND65. PND40 (CON, n = 9; MS, n = 10) and PND65 (CON, n = 13; MS, n = 15). n.s. not significant; *p < 0.05, **p < 0.01, and ***p < 0.001 as compared with controls. The data are represented as mean ± SEM