Hu Fan, Li Guangxing, Liang Zhen, Yang Yun, Zhou Yifeng
Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230027, PR China.
Brain Res Bull. 2008 Sep 30;77(2-3):77-83. doi: 10.1016/j.brainresbull.2008.06.007. Epub 2008 Jul 16.
Morphine exposure may have a negative effect on the receptive field properties of neurons in primary visual cortex of cats. The present experiment used morphological methods in order to investigate whether chronic morphine treatment also affects dendritic characters of these neurons. According to the Sholl analysis and dendritic branch order analysis, we obtained the dendritic length and calculated the spine density on dendrites of the pyramidal neurons in layer III and the spiny stellate neurons in layer IV. The results showed that morphine exposure induced significant decreases in the total dendritic length and spine density on both pyramidal and spiny stellate neurons. The further branch order analysis revealed that spine density was decreased at every (first to fourth) branch order of dendrites of pyramidal and spiny stellate neurons. Decrease in dendritic length of the pyramidal neurons was observed only at the fourth branch order, while the spiny stellate neurons had shorter dendrite at the second and third branch order. These findings may underlie the degradation of receptive field properties of the primary visual cortex neurons following chronic morphine exposure.
吗啡暴露可能会对猫初级视觉皮层神经元的感受野特性产生负面影响。本实验采用形态学方法，以研究慢性吗啡处理是否也会影响这些神经元的树突特征。根据肖尔分析和树突分支顺序分析，我们获得了树突长度，并计算了Ⅲ层锥体细胞和Ⅳ层棘状星形细胞树突上的棘密度。结果表明，吗啡暴露导致锥体细胞和棘状星形细胞的总树突长度和棘密度显著降低。进一步的分支顺序分析显示，锥体细胞和棘状星形细胞树突的每个（第一至第四）分支顺序的棘密度均降低。仅在第四分支顺序观察到锥体细胞的树突长度减少，而棘状星形细胞在第二和第三分支顺序的树突较短。这些发现可能是慢性吗啡暴露后初级视觉皮层神经元感受野特性退化的基础。
