Studies of ion channel pharmacology have witnessed considerable developments during the past half a century. Whereas voltage clamp techniques were applied to neuropharmacology for the studies of some chemicals in the late 1950s, it was not until 1960s that cellular neuropharmacological studies started flourishing when tetrodotoxin was discovered to exert a selective and potent block of the sodium channels. The progress in this field was greatly accelerated when patch clamp techniques developed in the early 1980s. Incorporation of molecular biology into this area further promoted the development, and cellular neuropharmacology has now become one of the most important biomedical sciences. A variety of cultured neurons are being used for research nowadays depending on the aims of study. In this chapter, variations of cell culture techniques are described in the former half of the chapter. The latter half is devoted to a few representative examples of our studies using cultured neurons.