Since the identification of endogenous H₂S in the mammalian brain in 1989, studies of this molecule uncovered physiological roles in processes such as neuromodulation, vascular tone regulation, cytoprotection against oxidative stress. We previously demonstrated that H₂S induces Ca²⁺ influx in astrocytes by activating transient receptor potential (TRP) channels. During this study we found that H₂S_n activates TRP ankyrine 1 (TRPA1) channels much more potently than does H₂S and that 3-mercaptopyruvate sulfurtransferase (3MST) produces H₂S₂ and H₂S₃. Recently, we demonstrated that the chemical interaction of H₂S with nitric oxide (NO) generates H₂S₂ and H₂S₃ that may be a mechanism of a synergistic effect between H₂S and NO we previously showed in the regulation of vascular tone. We showed that cysteine persulfide (Cys-SSH) together with its glutathione (GSH) counterpart (GSSH), both of which have been proposed to be involved in redox homeostasis, are also produced by 3MST. We will show our recent observation that sulfite protects neurons from oxidative stress more efficiently than H₂S and H₂S_n with a distinctive mechanism.