ArticleBasic and clinical neuroscience2016
Morphine-Induced Analgesic Tolerance Effect on Gene Expression of the NMDA Receptor Subunit 1 in Rat Striatum and Prefrontal Cortex.
Article in Basic and clinical neuroscience, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.
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Who cites it
2 citing papers in PubMed, 7 citations in OpenAlex.
- Transcriptional Reprogramming of GPCR Signaling Pathways in the Frontal Cortex of Morphine Dependent Mice.Biomolecules & therapeutics · 2026Article
- Effects of Acute and Subchronic Anodal Transcranial Direct Current Stimulation (tDCS) on Morphine-Induced Responses in Hotplate Apparatus.Galen medical journal · 2019Article
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3 authors at 1 institution in 1 country.
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Abstract
introductionMorphine 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.
methodsMorphine (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.
resultsThe 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).
conclusionTherefore, changes in the NR1 gene expression in rat striatum and PFC have a region-specific association with morphine-induced analgesic tolerance.
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