Agmatine was first identified and characterized as a candidate for CDS (clonidine displacing substance) in the bovine brain in 1994. The following researches demonstrated that agmatine was a widely distributed endogenous substance and performed a lot of biological functions in the central nervous system. The evidences revealed its targets were diverse and its mechanisms were complicated. Now it is well accepted that agmatine is a new neurotransmitter and/or neuromodulator and it might be an endogenous ligand of imidazoline receptor.

ASICs are H+-gated novel cation ion channels, which belong to the epithelial sodium channels (NaC/DEG) superfamily. As recent studies focus, ASICs are expected to be pharmacological targets on protecting the neuron from ischemia and damage, improving the ability of memory and study, curing epilepsy and analgesia. It is not until the most recentness that the subunits of ASICs have been cloned. Now, researchers have paid more attention to the distribution, expression, function and modulation of ASICs in the organism.