Figure 1.

A) Bottom view of the IVC cage lid for the dIVC, showing air inflow and outflow ports, receptacle for the water bottle, and the filter surrounding the outflow port. B) The plastic piece that holds the 6.2 × 7.3 cm, rectangular, Reemay spun-fiber filter surrounding the outflow port has been removed, showing the filter and the 3.0 × 5.6 cm trapezoid-shaped opening in the lid (large red arrow). C) Two of 14 approximately 3-mm-diameter holes in the plastic holder (small red arrows) that allow air exchange through the filter.