introduction: although formalin-induced activity in primary afferent fibers and spinal dorsal ‎horn is well described, the midbrain neural basis underlying each phase of behavior in ‎formalin test has not been clarified. the present study was designed to investigate the nucleus ‎cuneiformis (cnf)‎‏ ‏neuronal responses during two phases after subcutaneous injection of ‎formalin into the hind paw...

introduction: nucleus cuneiformis (ncf), as part of descending pain inhibitory system, cooperates with periaqueductal gray (pag) and rostral ventromedial medulla (rvm) in supraspinal modulation of pain. cannabinoids have analgesic effects in the pag, rvm and ncf. the transient receptor potential vanilloid type 1(trpv1) can be activated by anandamide and win55,212-2 as a cannabinoid receptor ago...

BACKGROUND Amiloride has been reported to produce a wide variety of actions, thereby affecting several ionic channels and a multitude of receptors and enzymes. Intrathecal α2-adrenergic receptor agonists produce pronounced analgesia, and amiloride modulates α2-adrenergic receptor agonist binding and function, acting via the allosteric site on the α2A-adrenergic receptor. OBJECTIVES To investi...

Introduction: Calcium/calmodulin-dependent protein kinase II (CaMKII) is highly expressed in the hippocampus, which has a pivotal role in reward-related memories and morphine dependence. Methods: In the present study, morphine tolerance was induced in male Wistar rats by 7 days repeated morphine injections once daily, and then gene expression profile of α-isoform of CaMKII (CaMKIIα) in the hipp...

abstract  introduction: diabetic rats display exaggerated hyperalgesic behavior in response to noxious stimuli that may resemble and model aspects of painful diabetic neuropathy in humans. this study was designed to investigate the effect of nigella sativum (ns) on formalin-induced nociceptive responses (standard formalin test) in streptozotocin (stz)-induced diabetic rats.  methods: for this p...

objective(s): we aimed to examine association of gene expression of mor1 and glun1 at mrna level in the lumbosacral cord and midbrain with morphine tolerance in male wistar rats. materials and methods: analgesic effects of morphine administrated intraperitoneally at doses of 0.1, 1, 5 and 10 mg/kg were examined using a hot plate test in rats with and without a history of 15 days morphine (10 mg...

introduction: several researches have reported that stress is able to inhibit the development of morphine tolerance via activating of hypothalamic-pituitary-adrenal (hpa) axis. in the present study we tried to examine the effect of epinephrine, the product of adrenal medulla, on the development of morphine tolerance. methods: analgesic tolerance was induced by intrathecal (i.t.) injection of mo...

BACKGROUND Alpha 2 (α(2))-adrenoceptor agonists may be useful for their potential to increase or prolong opioid analgesia while attenuating the development of opioid tolerance. The purpose of this study was to investigate the effects of dexmedetomidine and guanfacine (α(2)-adrenoceptor agonists) on morphine analgesia and tolerance in rats. METHODS Adult male Wistar albino rats weighing 195-20...

BACKGROUND The stimulation of acupoints along the meridians, but not the non-acupoints outside of the meridians, produces analgesia. Although the acupoint is defined at the body surface, the exact location of the acupoints is not known. This study aims to examine whether the intensity and duration of the analgesic effect of electroacupuncture (EA) at the Zusanli (ST36) and Sanynjiao acupoints (...