Distinct expression of synaptic NR2A and NR2B in the central nervous system and impaired morphine tolerance and physical dependence in mice deficient in postsynaptic density-93 protein
2008

Effects of PSD-93 on Morphine Tolerance in Mice

Sample size: 76 publication 10 minutes Evidence: high

Author Information

Author(s): Liaw Wen-Jinn, Zhu Xu-Guang, Yaster Myron, Johns Roger A, Gauda Estelle B, Tao Yuan-Xiang

Primary Institution: Johns Hopkins University School of Medicine

Hypothesis

Does PSD-93 deficiency affect synaptic NR2A and NR2B expression and morphine tolerance in mice?

Conclusion

PSD-93 deficiency impairs morphine tolerance and physical dependence due to reduced NR2A and NR2B expression in specific brain regions.

Supporting Evidence

  • PSD-93 deficiency reduced NR2A and NR2B levels in the dorsal horn and forebrain cortex.
  • Morphine tolerance was significantly impaired in PSD-93 knockout mice compared to wild type.
  • Knockout mice showed abnormal pain sensitivity after repeated morphine injections.
  • The study suggests that PSD-93 is crucial for NMDAR-dependent neuronal plasticity.

Takeaway

Mice without a protein called PSD-93 have trouble handling morphine, which means they don't get used to it like normal mice do.

Methodology

The study used PSD-93 knockout mice and wild type mice to assess morphine tolerance and dependence through various behavioral tests.

Potential Biases

Potential bias due to the experimenter's knowledge of the genotype during behavioral assessments.

Limitations

The study primarily focused on specific brain regions and may not generalize to all aspects of opioid tolerance.

Participant Demographics

Male PSD-93 knockout and wild type mice aged 10-12 weeks.

Statistical Information

P-Value

p<0.01

Confidence Interval

95% CI: 1.89–2.99 mg/kg

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1186/1744-8069-4-45

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