Functional comparison of corticostriatal and thalamostriatal postsynaptic responses in striatal neurons of the mouse
Functional comparison of corticostriatal and thalamostriatal postsynaptic responses in striatal neurons of the mouse
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DOI：
10.1007/s00429-017-1536-6
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发表时间：
2018-04-01
影响因子：
3.1
通讯作者：
Galarraga, E.
中科院分区：
文献类型：
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作者：
Arias-Garcia, M. A.;Tapia, D.;Galarraga, E.
在电生理学定义的纹状体细胞类别中比较来自皮层和丘脑的突触输入：直接和间接通路的纹状体投射神经元（dSPN和iSPN）、快速尖峰中间神经元（FS）、胆碱能中间神经元（ChIN）和低阈值尖峰样（LTS样）中间神经元。我们的目的是观察来自皮层或丘脑的刺激是否具有相同的突触强度，以引起这些神经元类的长时间阈上突触反应。阈下反应表明，从任何一个来源的输入功能混合在他们的树突在类似的电紧张距离他们的胞体。纹状体神经元类别的被动和主动特性与之前的研究一致。使用含有Td-Tomato或eYFP荧光蛋白的Cre依赖性腺相关病毒来鉴定靶细胞。使用Vglut-2-Cre小鼠在板内丘脑核中用启动子CamKII或EF1.DIO驱动的ChR 2-eYFP转染，或在运动皮质中用CAMKII驱动的ChR 2-eYFP转染用于光遗传学刺激皮质或丘脑传入。两个领域的刺激在皮质或光刺激的ChR 2-YFP皮质纤维诱发类似的延长阈上反应在SPN。光刺激ChR 2-YFP丘脑传入也诱发阈上反应。在这两种情况下都观察到了先前描述的dSPN和iSPN反应之间的差异。延长的阈上反应也可以从这两个来源诱发到所有其他神经元类的研究。然而，引起丘脑纹状体阈上反应，传入来自一个以上的丘脑核团被刺激。总之，丘脑和皮质都能够产生阈上反应，汇聚在不同的纹状体细胞类别。突触后特性似乎塑造了这些反应。
Synaptic inputs from cortex and thalamus were compared in electrophysiologically defined striatal cell classes: direct and indirect pathways' striatal projection neurons (dSPNs and iSPNs), fast-spiking interneurons (FS), cholinergic interneurons (ChINs), and low-threshold spiking-like (LTS-like) interneurons. Our purpose was to observe whether stimulus from cortex or thalamus had equivalent synaptic strength to evoke prolonged suprathreshold synaptic responses in these neuron classes. Subthreshold responses showed that inputs from either source functionally mix up in their dendrites at similar electrotonic distances from their somata. Passive and active properties of striatal neuron classes were consistent with the previous studies. Cre-dependent adeno-associated viruses containing Td-Tomato or eYFP fluorescent proteins were used to identify target cells. Transfections with ChR2-eYFP driven by the promoters CamKII or EF1.DIO in intralaminar thalamic nuclei using Vglut-2-Cre mice, or CAMKII in the motor cortex were used to stimulate cortical or thalamic afferents optogenetically. Both field stimuli in the cortex or photostimulation of ChR2-YFP cortical fibers evoked similar prolonged suprathreshold responses in SPNs. Photostimulation of ChR2-YFP thalamic afferents also evoked suprathreshold responses. Differences previously described between responses of dSPNs and iSPNs were observed in both cases. Prolonged suprathreshold responses could also be evoked from both sources onto all other neuron classes studied. However, to evoke thalamostriatal suprathreshold responses, afferents from more than one thalamic nucleus had to be stimulated. In conclusion, both thalamus and cortex are capable to generate suprathreshold responses converging on diverse striatal cell classes. Postsynaptic properties appear to shape these responses.