Basic and Clinical Neuroscience Journal
مجله علوم اعصاب پایه و بالینی
BCN
Medical Sciences
http://bcn.iums.ac.ir
137
journal137
2008-126X
2228-7442
10.32598/bcn
en
jalali
1395
4
1
gregorian
2016
7
1
7
3
online
1
fulltext
en
Morphine-Induced Analgesic Tolerance Effect on Gene Expression of the NMDA Receptor Subunit 1 in Rat Striatum and Prefrontal Cortex
Cellular and molecular Neuroscience
Cellular and molecular Neuroscience
Original
Original
<p dir="ltr" style="text-align: justify;"><strong>Introduction:</strong> Morphine is a potent analgesic but its continual use results in analgesic tolerance. Mechanisms of this tolerance remain to be clarified. However, changes in the functions of μ-opioid and N-Methyl-D-aspartate (NMDA) receptors have been proposed in morphine tolerance. We examined changes in gene expression of the NMDA receptor subunit 1 (NR1) at mRNA levels in rat striatum and prefrontal cortex (PFC) after induction of morphine tolerance.<br>
<strong>Methods: </strong>Morphine (10 mg/kg, IP) was injected in male Wistar rats for 7 consecutive days (intervention group), but control rats received just normal saline (1 mL/kg, IP). We used a hotplate test of analgesia to assess induction of tolerance to analgesic effects of morphine on days 1 and 8 of injections. Later, two groups of rats were sacrificed one day after 7 days of injections, their whole brains removed, and the striatum and PFC immediately dissected. Then, the NR1 gene expression was examined with a semi-quantitative RT-PCR method.<br>
<strong>Results:</strong> The results showed that long-term morphine a administration induces tolerance to analgesic effect of the opioid, as revealed by a significant decrease in morphine-induced analgesia on day 8 compared to day 1 of the injections (P<0.001). The results also showed that the NR1 gene expression at mRNA level in rats tolerant to morphine was significantly increased in the striatum (P<0.01) but decreased in the PFC (P<0.001).<br>
<strong>Conclusion:</strong> Therefore, changes in the NR1 gene expression in rat striatum and PFC have a region-specific association with morphine-induced analgesic tolerance.</p>
Morphine, Gene expression, Prefrontal cortex, Corpus striatum
241
248
http://bcn.iums.ac.ir/browse.php?a_code=A-10-373-3&slc_lang=en&sid=1
Shamseddin
Ahmadi
sh.ahmadi@uok.ac.ir
1370031947532846007928
1370031947532846007928
Yes
Department of Biological Science and Biotechnology, Faculty of Science, University of Kurdistan, Sanandaj, Iran.
Fatemeh
Rafieenia
f.rafieenia@uok.ac.ir
1370031947532846007929
1370031947532846007929
No
Department of Biological Science and Biotechnology, Faculty of Science, University of Kurdistan, Sanandaj, Iran.
Jalal
Rostamzadeh
j.rostamzadeh@uok.ac.ir
1370031947532846007930
1370031947532846007930
No
Department of Biological Science and Biotechnology, Faculty of Science, University of Kurdistan, Sanandaj, Iran.