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Long-term morphine addiction reduces neurogenesis and memory performance and alters emotional reactivity and anxiety levels in male rats

Authors Famitafreshi H, Karimian M, Marefati N

Received 30 April 2015

Accepted for publication 9 June 2015

Published 17 July 2015 Volume 2015:7 Pages 129—136


Checked for plagiarism Yes

Review by Single-blind

Peer reviewer comments 2

Editor who approved publication: Dr Peter Koulen

Hamidreza Famitafreshi, Morteza Karimian, Narges Marefati

Department of Physiology, Tehran University of Medical Sciences-International Campus, Tehran, Iran

Introduction: Substance abuse is a behavioral disorder associated with a wide variety of devastating effects. Neurogenesis in dentate gyrus of hippocampus is essential for brain functions like memory formation. Therefore, this may play an important role in achieving successful withdrawal.
Methods and materials: Twenty Sprague-Dawley rats were randomly divided into two experimental groups: control and addiction. To induce morphine dependence, animals received morphine (0.75 mg/rat) for 21 days. The performance of animals in Morris water maze and elevated plus maze tests was evaluated after day 20. At the end of the study, the rats were decapitated, and their brains were sectioned to study neurogenesis by counting BrdU-positive cells.
Results: Hippocampal neurogenesis was significantly reduced in rats in the addicted group. Also, reference and working memory performance were impaired in animals in the addicted group. A decrease in emotional reactivity and anxiety was observed in animals in the addicted group when compared with that in the control group.
Conclusion: Addiction adversely affects brain functions and neurogenesis; thus treatment to increase neurogenesis is the better option for the persons with substance abuse.

Keywords: hippocampal neurogenesis, morphine addiction, striatum, morphine-induced, hippocampus, substance abuse

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