Figure 3.

Assessment of the modulatory effects of intermittent fasting on chronic cerebral hypoperfusion (CCH)-induced synaptic loss and ultrastructural alteration. (A and B) Representative transmission electron microscopy (TEM) images (A) and corresponding quantification (B) demonstrated significant decrease in synaptic density in AL-CCH mice in prefrontal cortex region at both day 7 and day 30 post-CCH, with no significant differences observed between IF-CCH and sham groups. (C and D) Ultrastructural analysis of the g-ratio indicated thinner cortical myelin sheaths (reflected by a higher g-ratio) in both AL-CCH and IF-CCH mice at day 30 compared to control (D). (E and F) Representative TEM images and quantification showed a marked increase in postsynaptic density (PSD) length (did not reach significant level) in both AL-CCH and IF-CCH groups only at day 7 post CCH compared to sham controls. (G and H) A significant increase in the number of mushroom-shaped spine in AL-CCH mice at day 30 post-CCH, with no difference observed between IF-CCH and sham. TEM images were taken at 10000 magnification, scale bar: 600 nm. (I and J) Representative IMARIS images and quantification illustrate a significant upregulation in microglial engulfment of the postsynaptic protein PSD95 in AL-CCH mice at day 7 post-CCH. Scale bar: 5 µm. Data are represented as mean ± S.E.M. n = 3-4 mice in each experimental group. *P < 0.05, **P < 0.01.