By a News Reporter-Staff News Editor at Pain & Central Nervous System Week -- Research findings on Analgesics are discussed in a new report. According to news reporting out of Irbid, Jordan, by NewsRx editors, research stated, "Intracranial self-stimulation (ICSS) is an operant procedure in which responding is maintained by electrical brain stimulation. Stimulation frequency can be varied rapidly to maintain a wide range of baseline response rates, and drugs' effects can be evaluated simultaneously on both low ICSS rates maintained by low stimulation frequencies and high ICSS rates maintained by high stimulation frequencies."
Our news journalists obtained a quote from the research from the University of Jordan, "ICSS facilitation' indicates drug-induced increases in low ICSS rates and is often considered an abuse-related effect, whereas ICSS depression' indicates decreases in high ICSS rates and may indicate abuse-limiting effects. This study examined the roles of mu-agonist efficacy and of previous mu-agonist exposure as determinants of mu-agonist effects on ICSS in rats with electrodes implanted into the medial forebrain bundle. The high-efficacy, intermediate-efficacy, and low-efficacy mu agonists methadone, fentanyl, and nalbuphine were tested during escalating regimens of morphine exposure (vehicle, 3.2, and 18 mg/kg/day). During vehicle treatment, methadone and fentanyl primarily depressed ICSS, whereas nalbuphine produced weak facilitation that was not dose dependent. Chronic morphine produced tolerance to ICSS depression and increased expression of ICSS facilitation."
According to the news editors, the research concluded: "These results suggest that mu-agonist exposure increases the expression of abuse-related ICSS facilitation by mu agonists with a broad range of efficacies at mu receptors."
For more information on this research see: Abuse-related effects of mu-opioid analgesics in an assay of intracranial self-stimulation in rats: modulation by chronic morphine exposure. Behavioural Pharmacology, 2013;24(5-6):459-470. Behavioural Pharmacology can be contacted at: Lippincott Williams & Wilkins, 530 Walnut St, Philadelphia, PA 19106-3621, USA. (Lippincott Williams and Wilkins - www.lww.com; Behavioural Pharmacology - journals.lww.com/behaviouralpharm/pages/default.aspx)
Our news journalists report that additional information may be obtained by contacting A.A. Altarifi, Jordan University of Science & Technology, Fac Med, Irbid, Jordan. Additional authors for this research include K.C. Rice and S.S. Negus (see also Analgesics).
Keywords for this news article include: Asia, Irbid, Jordan, Analgesics, Pain Medicine
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