Figure 4
From: Histamine impairs midbrain dopaminergic development in vivo by activating histamine type 1 receptors
HA does not alter BrdU incorporation but increases apoptotic cell death of proliferating VM NSPC by activating H 1 R. The effect of HA on proliferation and apoptotic cell death was evaluated by BrdU incorporation and TUNEL assays, respectively. (A) Micrographs showing immunostaining to detect BrdU-positive cells. Hoechst was used for visualization of nuclei. (B) Percentage of BrdU-positive cells. No statistically significant differences were found. (C) Micrographs showing TUNEL-positive cells (white arrows) and Hoechst-stained nuclei. One mM HA caused a significant increase in apoptotic cells, which was prevented by chlorpheniramine. (D) Percentage of the total cell number of TUNEL-positive cells. One millimolar HA-treatment increased the proportion of apoptotic cells compared to control condition. *p < 0.05; **p < 0.01; ***p < 0.001. The H1R antagonist chlorpheniramine significantly reverted this effect. ##p < 0.01 compared to 1 mM HA. Scale bars = 100 μm.