Single dose of morphine produced a prolonged effect on dopamine neuron activities
2008

Effects of a Single Dose of Morphine on Dopamine Neuron Activity

Sample size: 8 publication Evidence: moderate

Author Information

Author(s): Zhang Die, Zhang Hai, Jin Guo-zhang, Zhang Kehong, Zhen Xuechu

Primary Institution: State Key Laboratory of Drug Research, Department of Neuropharmacology, Shanghai Institute of Material Medica, Chinese Academy of Sciences, Shanghai, PR China

Hypothesis

A single exposure to morphine induces changes in dopamine neuron activities in the ventral tegmental area.

Conclusion

Single morphine exposure leads to prolonged activation of dopamine neurons and desensitization of opiate receptors, which may contribute to dependence and tolerance.

Supporting Evidence

  • Acute morphine treatment significantly increased the firing rate and power of slow oscillation of dopamine neurons in naïve rats.
  • These changes lasted at least for 3 days following the morphine treatment.
  • Responses of the dopamine neurons to subsequent morphine challenge were diminished during this period.

Takeaway

When rats were given morphine just once, it made their brain cells that release dopamine work differently for a few days, which might make them want more morphine later.

Methodology

The study involved administering morphine to rats and measuring the firing activities of dopamine neurons in the ventral tegmental area at various time points.

Participant Demographics

Male Sprague-Dawley rats, weighing 270 to 300 g.

Statistical Information

P-Value

p<0.01

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1186/1744-8069-4-57

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