the aim of the present study was to investigate the effect of α2-adrenergic agonist (xylazine) andantagonist (yohimbine) on phasic pain during estrous cycle in female rats. adult female rats weighing 180-220 g were kept under controlled temperature (21-24°c) and light/dark conditions (light on at 6:00 a.m. and light off at 6:00 p.m.). animals were divided into four groups: 1) control group whic...

bulbospinal noradrenergic pathways are shown to have an important role in descending inhibition of pain sensation. locus ceruleus (lc), as a rich noradrenergic nucleus in the brain stem which has projections into the dorsal horn of the spinal cord, was evaluated for antinociceptive activity by using tonic and phasic pain models in the rat. lc-lesioned rats demonstrated moderate increase in both...

Bulbospinal noradrenergic pathways are shown to have an important role in descending inhibition of pain sensation. Locus ceruleus (LC), as a rich noradrenergic nucleus in the brain stem which has projections into the dorsal horn of the spinal cord, was evaluated for antinociceptive activity by using tonic and phasic pain models in the rat. LC-lesioned rats demonstrated moderate increase in ...

Pain perception is closely related to the attentional level and the vigilance of the subject [4]. The intensity of a pain stimulus and its sensation do often not coincide. A common experimental example is the so-called pain-inhibiting-pain effect: A stressful stimulus, e.g. persistent or chronic pain, often elevates the threshold for brief pain stimuli applied during the same time. Stressful st...

• Sex and type of mechanical stimulation strongly influence visceral pain. Responses to tonic stimuli are less intense compared those phasic stimuli. influences the responses but not stimulation. Visceral pain behavior may depend on abdominal musculature composition features. Estrogens modulate different pathways activated by be influenced many factors. The aim this study was analyze impact sex...

VIDEO ABSTRACT We compared brain activations in response to acute noxious thermal stimuli in controls and chronic back pain (CBP) patients. Pain perception and related cortical activation patterns were similar in the two groups. However, nucleus accumbens (NAc) activity differentiated the groups at a very high accuracy, exhibiting phasic and tonic responses with distinct properties. Positive ph...

  The paragigantocellularis (PGi) nucleus constitutes a large portion of the ventral pontomedullary reticular formation. Neurons within the PGi have been implicated in a variety of functions including cardiovascular regulation, respiratory control, pain and analgesia. Investigators have demonstrated that electrical stimulation and microinjection of L-glutamate into the PGi produce antinocicepti...

The analgesic efficacy of cholinergic agonists and anticholinesterase agents has been widely recognized. The analgesic effect obtained by activating cholinergic mechanisms, however, seems to depend on the experimental pain model utilized for its evaluation. The antinociceptive effect of intraspinal neostigmine was examined in rats submitted concurrently to the tail flick and formalin tests. Neo...

This study utilized the methodology of Functional Measurement theory to investigate the additivity of painful and non-painful thermally induced experiences at one body site with those produced by brief noxious and innocuous electrical stimuli at another. Forty healthy young subjects were tested, using a Peltier thermode to induce tonic pain and an electrocutaneous stimulator for presenting phas...