Fig. 4.

The effects of intra-PFN microinjection of naloxonazine alone and before morphine administration on corneal pain induced by topical corneal surface application of hypertonic saline. Data are the means ± SEM obtained from six rats. * p < 0.05 compared to normal saline microinjected group; ^† p < 0.05 compared to morphine (4 μg) microinjected group; ^‡ p < 0.01 compared to morphine (4 μg) microinjected group; and ^# p < 0.05 compared to naloxonazine (4 μg) + morphine (4 μg) microinjected group