The advancements of medical technology, improvements in medical care, and increased patients' life span make pain research and related drug development high priorities for both the research community and pharmaceutical companies. Rapid development of basic science research tools, such as techniques of flurometric labeling, genomic and proteomic high throughput screening, and genetically modified animals, promotes the swift acceleration of pain research to a stage allowing integrated investigations of pain processing mechanisms at the single cell and/or molecule level, and in a spatially...