Figure 2.

Reduced osmotic water permeability in AQP4-deficient olfactory epithelium. A) Left panel: diagram of the olfactory epithelium. Inset: calcein-stained OE. Right panel: schematic of perfusion chamber with freshly isolated olfactory epithelium immobilized on the nylon mesh and all surfaces exposed to solutions. Inset: perfusate exchange time as measured by perfusion with PBS followed by fluorescein-containing PBS. B) Left panel: representative calcein fluorescence recordings in response to hypoosmolar challenge. Solution osmolarities changed from 300 to 150 mosmol at upward deflections and 150 to 300 mosmol at downward deflections. Right panel: reciprocal exponential time constants for osmotic equilibration (τ⁻¹, in s⁻¹) in olfactory epithelium from wild-type and AQP4-null mice. Individual measurements (•) and mean ± se (○). *P < 0.001.