Fig. 2: H2S is detected by the mouse GG neurons.
From: Hydrogen sulfide as a potent predator-derived kairomone mediating fear-related responses in mice
a Immunostainings on GG tissue slices from OMP-GFP mice to test the neuronal activity using the rpS6 Marker after stimulation with H2O and H2S. Green, GFP expression in mature olfactory neurons. Blue, Dapi staining. White arrows, localization of zoomed areas. Scale bars: 20 μm. Quantification of rpS6 intensity for each neuron after H2O (control in white; n = 46 neurons; number of pups = 3) and H2S (grey; n = 53 neurons; number of pups = 3) stimulation. Values represented as mean standardized with aligned dot plots ±SEM. A two-tailed Mann–Whitney test was used to compare the two stimulations: **p < 0.01. b Microscopy images of a tissue slice of a mouse GG observed with a DIC contrast (Hv) showing neurons in green (GFP) and after Fura-2 loading. Scale bars: 20 µm. Intracellular calcium changes observed in one representative GG neuron (white arrow) with a TMT perfusion (100 µM), different H2S concentrations (1, 5, 12.5 and 25 µM) and a KCl perfusion (10 mM) to verify neuronal viability. Fura-2AM ratio (arbitrary units) and time (minutes). Bars indicate the perfusion times. c Intracellular calcium changes observed in one representative GG neuron with SBT, 2-PT, TMT (1/5000), H2S (25 µM) or KCl (10 mM) in a ACSF Ca2+ vs. in a ACSF Ca2+ free solution. d Ratio amplitude responses for each tested substance with in a ACSF Ca2+ vs. in a ACSF Ca2+ free solution for each neuron (SBT, n = 23; 2-PT, n = 6; TMT, n = 45; H2S, n = 42 neurons; number of pups = 3). Grey light lines connect the same neuron for the different tested conditions. e, f Intracellular calcium changes observed in one representative GG neuron after degassing the solution of H2S (25 µM) (H2S-depleted; e) and degassing the skunk secretions (Skunk H2S-depleted solution; f). Bars indicate the perfusion times. Ratio amplitude responses for each GG neuron for H2S (25 µM), H2S-depleted and H2S (25 µM) (e; n = 51; number of pups = 3) and for the experiments with the secretions of the skunk, skunk H2S-depleted and the skunk again (f; n = 11; number of pups = 1). Grey light lines connect the same neuron for the different tested conditions. Values represented as mean values with aligned dot plots in a before-after graph; a paired Wilcoxon test used, ***p < 0.001 (d–f).
