Brain-derived neurotrophic factor increases inhibitory synapses, revealed in solitary neurons cultured from rat visual cortex
Brain-derived neurotrophic factor increases inhibitory synapses, revealed in solitary neurons cultured from rat visual cortex
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DOI：
10.1016/j.neuroscience.2004.03.053
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发表时间：
2004-12
期刊：
影响因子：
3.3
通讯作者：
M. Palizvan;K. Sohya;K. Kohara;A. Maruyama;H. Yasuda;F. Kimura;T. Tsumoto
中科院分区：
文献类型：
--
作者：
M. Palizvan;K. Sohya;K. Kohara;A. Maruyama;H. Yasuda;F. Kimura;T. Tsumoto
为了阐明脑源性神经营养因子（BDNF）对GABA能突触的慢性作用，我们观察了长期应用BDNF 10-15天对大鼠视皮层单个GABA能神经元自贴（突触）的影响。孤立的神经元制剂被用来排除可能的污染BDNF的行动上的兴奋性神经元在解离的神经元培养或切片制备。用GABA A受体选择性拮抗剂荷包牡丹碱和抗GABA合成酶谷氨酸脱羧酶65抗体免疫细胞化学方法证实神经元为GABA能神经元。为了评价GABA能突触功能，在全细胞电压钳模式下记录诱发和/或微型抑制性突触后电流（IPSC）。浓度为100 ng/ml的BDNF处理增强了诱发的IPSC的振幅和微型IPSC的频率。相反，BDNF对两次连续激活诱发的微型IPSC的振幅和IPSC的成对脉冲比没有可检测的影响。为了评估形态学变化，神经元进行免疫细胞化学染色的微管相关蛋白2的抗体，可视化体树突状区域和突触蛋白I，可视化突触前位点。定量分析显示BDNF使索马体面积、初级树突数、树突分支点数、树突总长度和突触部位数增加。BDNF的这种作用在GABA能神经元的两个亚群中均可见，即小白蛋白阳性和阴性神经元。为了可视化功能活跃的突触前位点，神经元用苯乙烯基染料FM 1 -43染色。BDNF增加了与微型IPSC频率相关的染色位点的数量。这些结果表明，BDNF长期处理促进视皮层GABA能神经元树突和突触的发育。
To elucidate chronic actions of brain-derived neurotrophic factor (BDNF) on GABAergic synapses, we examined effects of a long-term application of BDNF for 10–15 days on autapses (synapses) of solitary GABAergic neurons cultured from rat visual cortex. Solitary neuron preparations were used to exclude a possible contamination of BDNF actions on excitatory neurons in dissociated neuron culture or slice preparations. Neurons were confirmed to be GABAergic pharmacologically with bicuculline, a selective antagonist for GABAAreceptors and immunocytochemically with antibody against glutamic acid decarboxylase 65, a GABA synthesizing enzyme. To evaluate GABAergic synaptic function, evoked and/or miniature inhibitory postsynaptic currents (IPSCs) were recorded in the whole-cell voltage-clamp mode. The treatment with BDNF at a concentration of 100 ng/ml enhanced the amplitude of evoked IPSCs and the frequency of miniature IPSCs. In contrast, BDNF did not have a detectable effect on the amplitude of miniature IPSCs and the paired pulse ratio of IPSCs evoked by two, successive activations. To evaluate morphological changes, neurons were immunocytochemically stained with antibodies against microtubule-associated protein 2, to visualize somatodendritic region and synapsin I, to visualize presynaptic sites. The quantitative analysis indicated that BDNF increased the area of soma, the numbers of primary dendrites and dendritic branching points, the total length of dendrites and the number of synaptic sites. Such an action of BDNF was seen in both subgroups of GABAergic neurons, parvalbumin-positive and -negative neurons. To visualize functionally active presynaptic sites, neurons were stained with a styryl dye, FM1-43. BDNF increased the number of stained sites that was correlated with the frequency of miniature IPSCs. These results suggest that the chronic treatment with BDNF promotes dendritic and synaptic development of GABAergic neurons in visual cortex.