Volume 6, Issue 3 (Autumn 2002)                   J Qazvin Univ Med Sci 2002, 6(3): 3-11 | Back to browse issues page

XML Persian Abstract Print


Download citation:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:

Gheibi N, Semnanian S, Fathollahi Y. The effect of Morphine injection in the periaqueductal gray matter on the neuronal responsiveness of nucleus reticularis paragigantocellularis to Formalin. J Qazvin Univ Med Sci. 2002; 6 (3) :3-11
URL: http://journal.qums.ac.ir/article-1-663-en.html
Abstract:   (11631 Views)
Abstract Background: Nucleus reticularis paragigantocellularis (PGi) has a very effective role in the supraspinal pain modulation. PGi as a rostroventromedial medulla (RVM) structure receives a major input from periaqueductal gray matter (PAG). Formalin as a peripheral noxious stimulus has biphasic nociception and behavioral manifestations. Objective: To assess morphine injection in the periaqueductal gray matter (PAG) on the neuronal responsiveness of nucleus reticularis paragigantocellularis (PGi) to formalin. Methods: The experimental subjects were male NMRI rats. Diluted formalin (2.5%) as a chemical noxious stimulus and morphine as an analgesic drug were used. Using single unit recording (An extracelluar recording electrophysiologic method) the research was done. Findings: Findings indicate that the responses of the PGi inhibitory neurons evoked by formalin were disinhibited by morphine microinjection in the PAG. In the excitatory neurons, morphine decreased the firing rate to the baseline activity. Conclusion: PGi inhibitory neurons are affected by the PAG’s GABAergic interneurons. Morphine blocks GABA released from these interneurons and results to off-cell disinhibition. On-cells suppressions are probably related to morphine effects directly.
Full-Text [PDF 1405 kb]   (2095 Downloads)    
Type of Study: Research | Subject: Physiology

Add your comments about this article : Your username or Email:
CAPTCHA

© 2020 All Rights Reserved | The Journal of Qazvin University of Medical Sciences

Designed & Developed by : Yektaweb