Pains arising from the viscera constitute a large portion of clinically treated pains. They are characterized by poor localization; immobility with tonic increases in muscle tone; and vigorous but nonspecific changes in autonomic function, such as changes in respiration, heart rate, and blood pressure. Tissue-damaging stimuli do not reliably produce visceral pain, so the study of visceral nocic...

Microglial cells appear to play a vital role in the initiation of certain neuropathic pain states. In order to initiate neuropathic pain, microglia need to be activated. Microglia activation in the spinal cord involves both hypertrophy as well as hyperplasia, progressing through a hypertrophic morphology, with thickened and retracted processes (observed within the first 24 hours after nerve inj...

Like most reviews on the pathophysiology of pain this lecture will mainly consider the physiology of nociceptiono Nociception like other sensory modalities is subserved by a specific array of nervous connexions which have been known in broad lines for many yearso A number ofneurosurgical operating procedures (cordotomy, tractotomy .oo) were based on this' knowledge. In recent years owing to maj...

Capsaicin, the pungent ingredient of the hot chili pepper, is known to act on the transient receptor potential cation channel vanilloid subfamily member 1 (TRPV1). TRPV1 is involved in somatic and visceral peripheral inflammation, in the modulation of nociceptive inputs to spinal cord and brain stem centers, as well as the integration of diverse painful stimuli. In this review, we first describ...

The study of pain in awake animals raises ethical, philosophical, and technical problems. We review the ethical standards for studying pain in animals and emphasize that there are scientific as well as moral reasons for keeping to them. Philosophically, there is the problem that pain cannot be monitored directly in animals but can only be estimated by examining their responses to nociceptive st...

described multiple potential factors whereby smoking may contribute to pain. Smith (5) has postulated a potential novel mechanism whereby smoking may contribute to inflammatory pain via its inhibitory actions on an enzyme known as leukotriene A4 hydrolase (LTA4H), --an action on the peptidase site of LTA4H revealed by Snelgrove et al(6). Epidemiologic studies have reported an association betwee...

In addition to its effect on reproductive organs, estrogen exhibits complex effects on brain structure, function and behavior. In this regard, the influence of gonadal hormones especially estrogens on nociception has recently been accepted. Soybean is known as an important phytoestrogen containing plant that is used as an alternative for estrogen replacement therapy. In this study, the influenc...

Introduction: Sub-chronic swim stress is known to induce a prolonged hyperalgesia, which is mediated through NMDA and opioid systems. Nitric oxide is a soluble gas, which acts as a retrograde messenger that modulates the release of mentioned neurotransmitters. It is also involved in nociception and memory. The aim of this study was to evaluate the role of NO pathway in nociception and memory...

Accurate discrimination of the intensity and spatial location of nociceptive stimuli is essential to guide appropriate behaviour. The ability to discriminate the attributes of sensory stimuli is continuously refined by practice, even throughout adulthood - a phenomenon called perceptual learning. In the visual domain, perceptual learning to discriminate one of the features that define a visual ...

A major gap in our understanding of sensation is how a single sensory neuron can differentially respond to a multitude of different stimuli (polymodality), such as propio- or nocisensation. The prevailing hypothesis is that different stimuli are transduced through ion channels with diverse properties and subunit composition. In a screen for ion channel genes expressed in polymodal nociceptive n...