ABSTRACT
This chapter presents all potential targets for new drugs are impossible and the opioids provide an excellent series of examples of how modern techniques can be used to seek new drugs. Opioid drugs, in particular, morphine, are the gold standards of analgesic therapy for moderate to severe pains. The models can be used to ascertain mechanisms and effects of drugs on the various components of this syndrome by the use of behavioral and electrophysiological approaches. There is a clear need for this multidisciplinary attack on the problem of neuropathic pain, as there is a danger of nonspecific drug effects in animal behavioral studies. Many factors can influence morphine analgesia, including the pathological loss of opioid receptors that can occur after nerve injury but also activity in other transmitter systems. The levels in the spinal cord of the non-opioid peptide, cholecystokinin has consequences for the level of opioid analgesic mechanisms.
