Pain is an extremely complex process that involves the interaction of an array of neurotransmitters and neuromodulators at all levels of the neuraxis. Identification of the receptors and processes that are involved in the transmission of pain at a spinal level has led to the use of new agents and new techniques in pain management. These include use of preemptive analgesia and use of techniques such as intrathecal drug administration and epidural spinal cord stimulation. This review presents some of the findings from basic research that have led to these developments, particularly those that relate to the changes that occur following inflammation and nerve injury.