Figure 4.

On an appetitive pattern separation task, mice exposed to ⁵⁶Fe IRR at 6-month of age distinguish two similar visual cues earlier and with greater accuracy on the last test day relative to Sham mice. (a) Sample touchscreen images for location discrimination training (LD train). (b–e) Sham and ⁵⁶Fe IRR mice performed similarly in LD train. (b) Distribution of subjects reaching criteria, (c) days to completion, (d) session completion time, (e) % correct. (f) Sample touchscreen images for LD testing (LD test). (g–j) ⁵⁶Fe IRR mice completed the LD test earlier than Sham (g,h), but no difference in session completion time (i) or number of completed trials (j). (k,l) ⁵⁶Fe IRR mice were more accurate overall (k) and on both “Large” and “Small” separation trials compared to Sham mice (l). (m–p) Sham and ⁵⁶Fe IRR mice made similar number of blank touches to non-stimuli windows (m) and had similar reward collection latency (n), correct image response latency (o), and incorrect image response latency (p). (q–t) Sham and ⁵⁶Fe IRR mice had similar block duration in each 10-trial block (q). However, ⁵⁶Fe IRR mice had higher accuracy in the 4^th 10-trial block (31^st–40^th trial) compared to Sham mice (r). Sham and ⁵⁶Fe IRR mice made similar number of blank touches in each block (s) and left and right touches during inter-trial interval (ITI) (t). Sham: n = 12, IRR: n = 12. Mean ± SEM. Mantel-Cox test, *p < 0.05 in b, g; Unpaired, two-tailed t-test in c-e, h-i, k, m-p; Two-way RM ANOVA,*p < 0.05, **p < 0.01, post hoc: Bonferroni in j, l, q-t, a p < 0.05, a’ p < 0.01 in Sham vs.⁵⁶Fe mice in l, r, c’ p < 0.01 1^st and 4^th block in ⁵⁶Fe mice in s. s = seconds.