Fig. 3. In vivo osteocyte mechanotransduction is affected by Chrna1 and Rapsn cKO in a sexually dimorphic way.

Intravital imaging of osteocyte Ca²⁺ signaling responses to mechanical loading was used to assess molecular level functional impacts of either Chrna1 or Rapsn cKO. (A) In males, the percentage of responding osteocytes decreased with Chrna1 cKO at very low strains but increased at higher strains for both Chrna1 and Rapsn cKO. (B) Rapsn cKO also increased response intensity among responding cells at three of the five strain levels tested. These results indicate dysregulation of mechanosensation in male osteocytes with ACh signaling disruption. (C and D) While female response intensities were unaltered, the number of responding cells was decreased at lower strain values tested for Chrna1 cKO mice compared to controls. t tests were performed across groups within each strain level (*P < 0.05; **P < 0.01). Sample sizes are as follows: % Cells responding: (GCaMP: 7 to 9, Chrna1: 9 to 10, Rapsn: 12 to 14). Delta F: (GCaMP: 3 to 9, Chrna1: 2 to 10, Rapsn: 4 to 14).