Pain is an unpleasant but very important biological signal for danger. Nociception is necessary for survival and maintaining the integrity of the organism in a potentially hostile environment. Pain is both a sensory experience and a perceptual metaphor for damage and it is activated by noxious stimuli that act on a complex pain sensory apparatus. However, chronic pain having no more a protective role can become a ruining disease itself, termed "neuropathic pain".

Introduction.- Functional neuroanatomy of the pain system.- Primary afferent neuron.- Distribution of nociceptor peripheral endings.- Termination in the spinal cord and spinal trigeminal nucleus.- Ascending pathways of the spinal cord and of the STN.- Dorsal column nuclei and nociception.- Cerebellum and nociception.- Cortices involved in pain perception and thalamocortical projection.- Descending modulatory pathways.- Neuropathic pain.- Central changes consequent to peripheral nerve injury.- The role of glial cells.- Neuropathology of herpes zoster (HZ) and of postherpetic neuralgia (PHN).- Diabetic neuropathic pain.- Cancer neuropathic pain.- Central neuropathic pain.- Concluding remarks.- Summary.- Subject index.