Fig. 5: The physiological effects and fear-related behaviors induced by H2S are dependent of a functional GG.
From: Hydrogen sulfide as a potent predator-derived kairomone mediating fear-related responses in mice
a–c Effects of the H2S exposure (125 µM; grey bars) on plasma corticosterone level (n = 7 for H2O and n = 10 for H2S) (a), on blood pressure (systolic, diastolic and mean) (n = 6 for H2O and n = 6 for H2S) (b) and heart rate measured in beats per minute (BPM, n = 6 for H2O and n = 6 for H2S) (c) compared to the exposition to the H2O (control, white bars). Mean ± SEM with aligned dot plots. A one-tailed Mann–Whitney test (a), a paired Student’s t test (b) and a paired Wilcoxon test (c) were used to compare the two conditions, *p < 0.05. d Open field arena (BioRender) delimited in three different zones: a safety, central and danger zone (orange rectangles). Blotting papers with H2O (white square) or H2S (grey square) are localized in the middle of the arena width. Scale bar: 5 cm. Mice were tracked for 5 min, and 200 μL of the tested solutions (H2O or H2S, 25 or 125 µM) were added on the blotting paper. Representative tracking of one mouse (black line) is shown. e Quantification of the stress-related behaviors according to the control and displayed as indexes (%) in the presence of H2O (in white) and of H2S (in grey). Total distance travelled, number of entries in central zone, distance travelled in central zone and number of entries in danger zone (125 µM H2S) and total time of freezing (25 µM H2S) were quantified (n = 14). Values expressed as mean ± SEM; paired Student’s t test used, *p < 0.05. Axo mice did not show any fear-related behaviors in the presence of H2S as shown on a representative tracking of one Axo mouse (black line) (f) and by the comparison of the different parameters (g) between Ctrl mice (results taken from (e) for H2S condition) and Axo mice in the presence of H2S. Values expressed as mean ± SEM; unpaired Student’s t test or Mann–Whitney test used, *p < 0.05; **p < 0.01. h Immunostainings on GG tissue slices to visualize the absence of GG neurons in axotomized (Axo) mice compared to Ctrl mice. GFP, in green, allows the precise localization of mature olfactory GG neurons. In blue, Dapi staining. Scale bars: 50 μm.
