| Popis: |
Transmission of somatosensory information is normally initiated in the periphery through stimulation of the endings of primary afferent neurons which encode information as an action potential discharge that is propagated into the central nervous system (CNS). Whether this information is ultimately perceived as noxious or innocuous depends, in part, on the activation of specific peripheral sensory afferents and, as importantly, on the actions and interactions of numerous neurotransmitter/neuromodulator systems at peripheral and central sites. The first level of central processing for most somatosensory information is in the dorsal horn of the spinal cord or in the homologous region of the trigeminal nucleus. Multiple lines of evidence support roles for adenosine and adenosine 5′-triphosphate (ATP) in the transmission of sensory information in the periphery and in the dorsal horn (Burnstock and Wood 1996; Salter et al. 1993; Sawynok 1998). In this chapter we review evidence that adenosine and ATP participate in sensory transmission, highlighting recent developments in our understanding of purine nucleotides and nucleosides in nociceptive, e.g., pain-related, and non-nociceptive sensory transmission at peripheral and spinal sites. Finally, we discuss results of humans studies which to date have focussed mainly on the use of adenosine as a novel therapeutic agent for the treatment of clinical pain. |
