Basic science and clinical pain research is particularly challenging for several reasons. First, pain is a subjective experience in response to nociception that follows actual or potential tissue damage. Since the ability to respond to this warning signal is essential for our survival, the nociceptive system that produces and transmits nociceptive signals is remarkably redundant and involves diffuse regions of the central nervous system. Second, unlike other sensory modalities, pain is a multi-dimensional experience including at least cognitive, affective, and sensory-discriminative components. Third, pain experiences can be influenced by psychological, socioeconomic, cultural, and genetic predispositions, making it exceedingly complicated to study pain and pain modulation. The topics covered in this volume are carefully selected and directly related to the daily practice of pain medicine. These topics include 1) central mechanisms of pain and pain modulation (Dickenson, Donovan-Rodriguez, Mattews) and clinical use of ion channel blockers (Chen); 2) spinal glutamatergic mechanisms (Guo, Dubner, Ren) and issues related to glutamate receptor antagonists in pain management (Mao); 3) basic science of opioid analgesics (Gintzler, Chakrabarti) and clinical opioid use (Smith, McCleane); 4) inflammatory cytokines (Samad) and clinical use of anti-inflammatory drugs (Fink, Brenner); 5) role of the sympathetic nervous system in pain mechanisms and its relation to clinical pain management (Sharma, Raja); 6) preclinical studies on tricyclic antidepressants (Gerner, Wang) and clinical use of antidepressants in pain management (Greenberg); 7) developing pain pathways and analgesic mechanisms during the developmental stage (Fitzgerald) and challenges of pediatric pain management (Lebel); 8) basic science mechanisms of serotonin agonists and their use in the clinical management of migraine headache (Biondi); 9) clinical research on gender differences in clinical pain and their implications for clinical pain management (Holdcroft); 10) current modalities of clinical cancer pain management (Popescu, Hord); and 11) preclinical and clinical information on alternative medicine (Chen).