Production of H2S in the nervous system is strictly regulated because overproduction of H2S has many detrimental effects, while inflammatory cytokines like interleukin-1β (IL-1β) mediated memory loss by stimulating expression of CBS that produces H2S. Furthermore, H2S has different signaling processes in the brain; for example, dysregulation of its metabolism is liable for neurodegeneration and also abnormal signaling of H2S is observed in case of AD and PD [98]. Here, CBS is linked to Alzheimer disease.