Figure 2.

Histamine (A) H₃ and (B) H₄ receptors expressed in the mouse spinal dorsal horn. Paraformaldehyde (4%)‐fixed adult murine spinal cords were dehydrated using sucrose infiltration, with 10% sucrose, then 20% sucrose made up with phosphate buffered saline, and snap‐frozen in iso‐pentane −70°C for 1 minute and stored at −80°C. Cryoslices (20 μm thickness) were probed with either (A) anti‐H₃ and (B) anti‐mH₄ receptor antibodies essentially as described previously [35, 38]. Arrows and arrowheads indicate H₃ and H₄ receptor expression, respectively. Bar = 200 μm.