Two Types of Thalamocortical Projections from the Motor Thalamic Nuclei of the Rat: A Single Neuron-Tracing Study Using Viral Vectors
Two Types of Thalamocortical Projections from the Motor Thalamic Nuclei of the Rat: A Single Neuron-Tracing Study Using Viral Vectors
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DOI：
10.1093/cercor/bhn231
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发表时间：
2009-09-01
期刊：
影响因子：
3.7
通讯作者：
Kaneko, Takeshi
中科院分区：
文献类型：
--
作者：
Kuramoto, Eriko;Furuta, Takahiro;Kaneko, Takeshi
使用表达膜靶向棕榈酰化位点附着的绿色荧光蛋白（palGFP）的病毒载体在大鼠脑中检查单个运动丘脑神经元的轴突分支。我们首先将丘脑腹侧前-腹外侧运动核分为1）口内侧部和2）尾外侧部，前者称为抑制性传入优势区（IZ），具有强的谷氨酸脱羧酶免疫反应性和弱的囊泡谷氨酸转运体2免疫反应性;后者称为兴奋性皮质下传入优势区（EZ），具有相反的免疫反应性。然后，我们通过注射稀释的palGFP-Sindbis病毒溶液标记了29个半球的38个运动丘脑神经元，并分离出10个IZ和EZ神经元用于重建。所有重建的IZ神经元不仅广泛地投射到大脑皮层，而且还投射到新纹状体，而EZ神经元几乎只将轴突投射到皮层。更有趣的是，47-66%的IZ神经元的轴突曲张在皮质区的I层中观察到。与此相反，只有2-15%的EZ神经元的静脉曲张被发现在第一层，大多数静脉曲张位于中间层。这些结果表明，2种形式的信息从基底神经节和小脑的差异提供给顶端和基底树突，分别皮质锥体神经元和整合，以产生一个电机执行命令。
The axonal arborization of single motor thalamic neurons was examined in rat brain using a viral vector expressing membrane-targeted palmitoylation site-attached green fluorescent protein (palGFP). We first divided the ventral anterior-ventral lateral motor thalamic nuclei into 1) the rostromedial portion, which was designated inhibitory afferent-dominant zone (IZ) with intense glutamate decarboxylase immunoreactivity and weak vesicular glutamate transporter 2 immunoreactivity, and 2) the caudolateral portion, named excitatory subcortical afferent-dominant zone (EZ) with the reversed immunoreactivity profile. We then labeled 38 motor thalamic neurons in 29 hemispheres by injecting a diluted palGFP-Sindbis virus solution and isolated 10 IZ and EZ neurons for reconstruction. All the reconstructed IZ neurons widely projected not only to the cerebral cortex but also to the neostriatum, whereas the EZ neurons sent axons almost exclusively to the cortex. More interestingly, 47-66% of axon varicosities of IZ neurons were observed in layer I of cortical areas. In contrast, only 2-15% of varicosities of EZ neurons were found in layer I, most varicosities being located in middle layers. These results suggest that 2 forms of information from the basal ganglia and cerebellum are differentially supplied to apical and basal dendrites, respectively, of cortical pyramidal neurons and integrated to produce a motor execution command.