Protein level of AQP4, detected with an antibody specific against the C-terminus of both M1 and M23 isoforms, decreased by 42% (from 107.6% ± 9.69 in control, to 62.55% ± 14.24) at 4 h (n = 7 and 3 in control and AOM-injected, respectively) and by 49% (to 58.98% ±4.52) at 24 h post-AOM injection (n = 7 and 5 in control and AOM-injected, respectively), the effects being separated by a return to control level at 12 h and 18 h post-AOM (Fig. 3B). Here, AQP4 is linked to infectious otitis media.