Chronic morphine exposure induces degradation of receptive field properties of LGN cells in cats  

作　　者：Li-hua HE Guang-xing LI Xiang-rui LI Yi- feng ZHOU 

机构地区：[1]Hefei National Laboratory for Physical Sciences at Microscale and School of Life Science, University of Science and Technology of China, Hefei 230027, China [2]Laboratory of Visual Information Processing, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China

出　　处：《Acta Pharmacologica Sinica》2005年第9期1034-1038,共5页中国药理学报（英文版）

基　　金：the National Natural Science Foundation of China(No 30470561).

摘　　要：Aim： To investigate the effect of chronic morphine exposure on the receptive field properties of lateral geniculate nucleus （LGN） neurons in cats. Methods： Cats were injected with morphine （10 mg/kg） or saline twice dally, for 10 d. Subsequently, extracellular single-unit recording techniques were used to examine the sensitivity of LGN neurons to visual stimuli in chronic morphine-treated and saline-treated cats. Results： Compared with saline-treated cats （as controls）, LGN neurons in morphine-treated cats had decreased signal-to-noise ratios （1.9 vs 3.1）, and orientation and direction sensitivity （0.103 vs O. 135 and 0.074 vs 0.10, respectively）, accompanied by significant increases in spontaneous （27.4 vs 17.5） and evoked activity （preferred： 42.2 vs 38.1; average： 28.1 vs 22.3）. Conclusion： Chronic morphine exposure can lead to the functional degradation of LGN neurons in cats, which might result from the effects of chronic morphine exposure on inhibitory neurotransmission.Aim： To investigate the effect of chronic morphine exposure on the receptive field properties of lateral geniculate nucleus （LGN） neurons in cats. Methods： Cats were injected with morphine （10 mg/kg） or saline twice dally, for 10 d. Subsequently, extracellular single-unit recording techniques were used to examine the sensitivity of LGN neurons to visual stimuli in chronic morphine-treated and saline-treated cats. Results： Compared with saline-treated cats （as controls）, LGN neurons in morphine-treated cats had decreased signal-to-noise ratios （1.9 vs 3.1）, and orientation and direction sensitivity （0.103 vs O. 135 and 0.074 vs 0.10, respectively）, accompanied by significant increases in spontaneous （27.4 vs 17.5） and evoked activity （preferred： 42.2 vs 38.1; average： 28.1 vs 22.3）. Conclusion： Chronic morphine exposure can lead to the functional degradation of LGN neurons in cats, which might result from the effects of chronic morphine exposure on inhibitory neurotransmission.

关 键 词：direction sensitivity orientation sensitivity signal-to-noise ratio spontaneous response evoked response 

分 类 号：R595.5[医药卫生—内科学] R742[医药卫生—临床医学]