Chronic morphine exposure alters the dendritic morphology of pyramidal neurons in visual cortex of rats

doi:10.1016/j.neulet.2007.03.023

Neuroscience Letters

Volume 418, Issue 3, 18 May 2007, Pages 227-231

https://doi.org/10.1016/j.neulet.2007.03.023 Get rights and content

Abstract

Repeated treatment of psychotropic drugs produces changes in brain and behavior that far outlast their initial neuropharmacological effects. The nature of persistent drug-induced neural plasticity is of interest because it is thought to contribute to the development of drug dependency and addiction. To determine if chronic morphine treatment alters the morphology of visual cortical neurons, we statistically examined the dendrites of layer III pyramidal neurons in the primary visual cortex of both morphine-treated and saline-control rats. Compared with control rats, the pyramidal cells of morphine-treated animals showed a significant decrease in the total dendritic length (24%) and a significant reduction (27%) in the dendritic spine density of dendritic arborization at the level of the second branch order. Our results suggest that some of the persistent neurobehavioral consequences and cognitive impairment resulting from repeated exposure to morphine may involve a reorganization of synaptic connectivity in visual cortical neurons.

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Acknowledgements

This investigation was supported by grants from the National Natural Science Foundation of China (30470561, 30070257), National Basic Research Program (2006CB500804), and State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences. Thank Dr. Jason Trageser for polishing the English.

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Chronic morphine exposure alters the dendritic morphology of pyramidal neurons in visual cortex of rats

Abstract

Section snippets

Acknowledgements

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The effects of morphine self-administration on cortical pyramidal cell structure in addiction-prone lewis rats

Cereb. Cortex

Chronic morphine impairs axoplasmic transport in the rat mesolimbic dopamine system

Neuroreport

Attenuation of tolerance to opioid-induced antinociception and protection against morphine-induced decrease of neurofilament proteins by idazoxan and other I2-imidazoline ligands

Br. J. Pharmacol.

Long-term plasticity at excitatory synapses on aspinous interneurons in area CA1 lacks synaptic specificity

J. Neurophysiol.

Bi-directional effects of GABA(B) receptor agonists on the mesolimbic dopamine system

Nat. Neurosci.

Regulation of nonphosphorylated and phosphorylated forms of neurofilament proteins in the prefrontal cortex of human opioid addicts

J. Neurosci. Res.

Marked decrease of immunolabelled 68 kDa neurofilament (NF-L) proteins in brains of opiate addicts

Neuroreport

Morphological Changes in the Nervous Systems arising from Behavioral Experience: What is the Evidence that they are involved in Learning and Memory?

Effects of morphine, d-amphetamine, and pentobarbital on shock and light discrimination performance in rats

Psychopharmacology (Berl.)