Portions of the brain stem seem normally to inhibit pain. In man and laboratory animals these brain areas and pathways from them to spinal sensory circuits can be activated by focal stimulation. Endogenous opioids appear to be implicated although separate nonopioid mechanisms are also evident. Stress seems to be a natural stimulus triggering pain suppression. Properties of electric footshock ha...

The evolutionary advantages to the suppression of pain during a stressful event (stress-induced analgesia (SIA)) are obvious, yet the reasoning behind sex-differences in the expression of this pain reduction are not. The different ways in which males and females integrate physiological stress responses and descending pain inhibition are unclear. A potential supraspinal modulator of stress-induc...

BACKGROUND Stress has paradoxical effects on pain, causing stress-induced analgesia but also exacerbating pain via poorly understood mechanisms. Adrenergic neurotransmission is integral in pathways that regulate the response to both pain and stress. Hyperalgesia is often associated with enhanced adrenergic sensitivity of primary afferents, but sympathetic nervous system outflow has not been dem...

introduction: based on human studies, inequality and social injustice have adverse effects on the individual and community health. in this study, the effects of food intake inequality and social status changes on pain perception and immunological factors were investigated in balb/c mice. methods: the present study was conducted by implementing different social stresses including food deprivatio...

Transcutaneous electrical nerve stimulation (TENS) is an analgesia inducing method with increasing applications in clinical procedures. In this study we tried to evaluate the role of the adrenergic system and its different adrenoceptor subtypes in TENS-induced analgesia. Two types of low and high frequency electrical stimuli were used in rats through needle electrodes, inserted at the base ...

in this study, we investigated the interactive effects of intraperitoneal (i.p.) injections of three different phosphodiesterase inhibitors (pdeis) on morphine-induced analgesia in mice using tail-flick method. subcutaneous administration of morphine (1, 3 and 6 mg/kg) caused significant antinociceptive effects in a dose dependent manner. administration of pentoxifylline (12.5, 25, 50 and 100 m...

Introduction: Topiramate is an anti-convulsant drug, which produces its effects via glutamate metabotropic receptors inhibition and/or GABA receptor excitation. In the present study, attempts were made to investigate the effects of topiramate on the tolerance to morphine-induced analgesia activity in male NMRI mice (20-30 g). Methods: Hot plate method was chosen for the study. First of all t...

BACKGROUND Imaging studies of pain processing in primary psychiatric disorders are just emerging. This study explored the neural correlates of stress-induced analgesia in individuals with posttraumatic stress disorder (PTSD). It combined functional magnetic resonance imaging (fMRI) and the traumatic script-driven imagery symptom provocation paradigm to examine the effects of trauma-related cues...