Volume 8, Issue 1 (January & February 2017 -- 2017)                   BCN 2017, 8(1): 51-60 | Back to browse issues page


XML Print


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

Khakpay R, Azaddar M, Khakpay F, Hatami Nemati H. Analgesic Effect of 17β-Estradiol on Nucleus Paragigantocellularis Lateralis of Male Rats Mediated Via GABAA Receptors. BCN 2017; 8 (1) :51-60
URL: http://bcn.iums.ac.ir/article-1-657-en.html
1- Department of Animal Science, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran.
2- Department of Biology, Faculty of Basics Sciences, Varamin Branch, Islamic Azad University, Pishva, Iran.
Abstract:  

Introduction: Beside its autonomic functions, the nucleus paragigantocellularis lateralis (LPGi) is involved in the descending pain modulation. 17β-Estradiol is a neuroactive steroid found in several brain areas such as LPGi. Intra-LPGi microinjection of 17β-estradiol can elicit the analgesic responses. 17β-Estradiol modulates nociception by binding to estrogenic receptors as well as allosteric interaction with other membrane-bound receptors like GABAA receptors. This study aimed to examine the role of GABAA receptors in the pain modulating effect of intra-LPGi injection of 17β-estradiol.
Methods: To study the antinociceptive effects of 17β-estradiol, cannulation into the LPGi nucleus of male Wistar rats was performed. About 500 nL of drug was administered 15 minutes prior to formalin injection (50 μL of 4%). Then, formalin-induced flexing and licking behaviors were recorded for 60 minutes. For evaluating the role of GABAA receptors in the estradiol-induced pain modulation, 17β-estradiol was administered into the LPGi nucleus 15 minutes after the injection of 25 ng/μL bicuculline (the GABAA receptor antagonist). Then, the formalin-induced responses were recorded.
Results: The results of the current study showed that intra-LPGi injection of 17β-estradiol decreased the flexing duration in both phases of formalin test (P<0.001); but it only attenuated the second phase of licking behavior (P<0.001). 17β-estradiol attenuated the second phase of formalin test of both behaviors (P<0.001). Bicuculline prevented the antinociceptive effect
of intra-LPGi 17β-estradiol in both first and second phases of formalin-induced responses (P<0.001).
Conclusion: According to the results of this study, the analgesic effect of intra-LPGi 17β-estradiol on the formalin-induced inflammatory pain might be mediated via GABAA receptors. 

Type of Study: Original | Subject: Behavioral Neuroscience
Received: 2016/02/26 | Accepted: 2016/08/22 | Published: 2017/01/1

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

Send email to the article author


Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

© 2024 CC BY-NC 4.0 | Basic and Clinical Neuroscience

Designed & Developed by : Yektaweb