Effect of Morphine Dependence on the Ultrastructure of Sprague-Dawley Rats

Objective: To investigate the ultrastructural changes of morphine dependent rat in the brain area of ventral tegmental area (VTA) and locus coeruleus (LC). Methods: The rats were given (sc) increasing doses of morphine to form morphine dependent models. The ultrastructural changes of the brain area of the above were observed by transmission electron microscope . Results: In the morphine dependent group,the neuronal nucleus of LC was irregular and swelling, there were vesiculations and dissolution of nuclear matrix in the nucleus of LC neuron , the rough endoplasmic reticulum was decreased, the free ribosomes were sparseness and the myelin figure was observed in cytoplasm of LC. Neuronal microfilament was abundant and myelinic degeneration of neuronal fibra was observed in nerve cell and neurogliocyte of VTA. Conclusion: Chronic exposure to morphine might induce ultrastructural changes in the brain area of VTA and LC which might contribute to the development of morphine dependence.