Analgesic targets: today and tomorrow.

Pain is recognized as a multifactorial sensory experience that is wholly unpleasant. It can vary in intensity from mild to severe and its duration can be anything from transient to persistent. Today we know so much more about the peripheral nociceptor as the primary detection apparatus for painful stimuli. We also understand in far greater detail the neurochemical mechanisms that occur at the level of the spinal cord and the complex interplay that exists between excitatory and inhibitory neural pathways. As a consequence of the assembly of this new body of evidence there are clear pointers that direct our attention to receptors, signaling pathways, enzymes and ion channels that all have the potential to be targets for novel, effective analgesics. The purpose of this review is to highlight some of the knowledge that has been assembled on this subject in recent years.