Fig. 7: Overexpression of NPTX1 in F-RAM ensemble rescued contextual memory imprecision in aged mice.
a, b Experimental scheme of CFC to test memory expression. c, d Freezing percentage (c) and discrimination index (d) of young and aged mice. Young, n = 11 mice; Aged, n = 10 mice. e, f Freezing percentage (e) and discrimination index (f) of young and aged mice. Young, n = 12 mice; Aged, n = 11 mice. g Diagram of AAV injection. h Experimental scheme for IM recording. i Representative traces of IM currents in F-RAM cells of young and aged mice. j Average IM current amplitudes recorded at –30 mV from young and aged mice. Young, n = 14 neurons from 3 mice; Aged, n = 15 neurons from 3 mice. k Representative confocal images of c-Fos+ cells colocalizing with Kv7.2. Green: c-Fos+ engram cells; purple: Kv7.2; blue: DAPI. Dashed white lines outline cell membrane. Scale bars, 5 μm. l Average membrane Kv7.2 fluorescence intensity of c-Fos+ neurons in young and aged mice. Young, n = 88 from 6 mice; Aged, n = 64 from 6 mice. m Co-IP of NPTX1 with Kv7.2 in DG of young and aged mice. n Quantification of immunoprecipitated Kv7.2 in young and aged mice. Young, n = 4 mice; Aged, n = 5 mice. o Diagram of AAV injection. p Experimental scheme of memory retrieval test. q Representative expression of NPTX1 in F- or N-RAM engram cells in DG. Green: F-RAM or N-RAM ensemble, EYFP or EGFP; blue: DAPI. Scale bars, 100 μm. r, s Freezing percentage (r) and discrimination index (s) of EYFP- and Nptx1-overexpressing aged groups (F-RAM). EYFP, n = 11 mice; Nptx1, n = 12 mice. t, u Freezing percentage (t) and discrimination index (u) of EYFP- and Nptx1-overexpressing aged groups (N-RAM). EYFP, n = 14 mice; Nptx1, n = 9 mice. Data are presented as mean ± SEM; *P < 0.05, **P < 0.01, ***P < 0.001.
