At the level of individual cells, signaling is crucial in cell division, differentiation, metabolic control and death. Reception of the signals depends on receptor proteins that are usually at the cell surface, and these receptor proteins bind the signal molecule. The binding activates the receptor, which in turn activates one or more of the intra-cellular signaling pathways. These relay chains of molecules, mainly intra-cellular signaling proteins, process the signal inside the receiving cell and distribute it to the appropriate intra-cellular targets. Cell signaling pathways are involved in the pathophysiology of many diseases and also in the mechanisms of action of many drugs, including local and general anesthetics. Knowledge of the basic cell signaling mechanisms is essential for understanding many of the pathophysiologic and pharmacologic mechanisms. Therefore, if we focus on applying the new cellular and molecular biologic research, these efforts could identify the mechanism of diseases and help develop new drugs in the field of anesthesiology and pain medicine.