Novel and distinct operational principles of intralaminar thalamic neurons and their striatal projections
Novel and distinct operational principles of intralaminar thalamic neurons and their striatal projections
复制标题
DOI：
10.1523/jneurosci.5519-06.2007
复制
发表时间：
2007-04-18
影响因子：
5.3
通讯作者：
Magill, Peter J.
中科院分区：
文献类型：
--
作者：
Lacey, Carolyn J.;Bolam, J. Paul;Magill, Peter J.
丘脑板内神经元，包括中央外侧核(CL)和束旁核(PF)，支配皮质和纹状体，对认知、感觉和运动过程起重要作用。我们验证了CL和PF神经元向纹状体提供不同功能输入的假设。我们记录了麻醉大鼠单个CL和PF神经元，并在细胞旁标记后，观察了它们的躯体树突特征和突触联系。所有CL神经元(n=31)在活体皮质慢波活动时都释放典型的低阈值钙峰爆发。相比之下，Pf神经元(n=52)很少发出这样的脉冲，而是以相对较低的频率发放群峰。CL和PF神经元的活动往往与皮层慢振荡有时间上的偶联。CL神经元具有典型的“浓密”树突，并优先与纹状体投射神经元的树突棘建立突触(占突触的91%)。PF神经元具有“网状”树突，平均而言，在纹状体内优先与树突建立突触(63%)，尽管神经元之间的连接明显不同。在所研究的六个PF神经元中，有两个专门针对树突，而另一个神经元几乎只针对棘突(97%)。因此，CL和PF神经元的基本特性不同(后者不表达丘脑中继神经元的典型工作原理)，它们向不同的纹状体靶点提供不同的时间模式输入。这种机制的多样性可能支持了特定和离散的信息从丘脑层内核到纹状体和皮质目标的传输。
Neurons of the intralaminar thalamus, including central lateral (CL) and parafascicular (Pf) nuclei, innervate the cortex and striatum and are important for cognitive, sensory, and motor processes. We tested the hypothesis that CL and Pf neurons provide functionally distinct inputs to the striatum. We performed recordings of single CL and Pf neurons in anesthetized rats and, after juxtacellularly labeling the neurons, their somatodendritic features and synaptic connections were characterized.All CL neurons ( n = 31) discharged classic low-threshold Ca2+ spike bursts during cortical slow-wave activity in vivo. In contrast, Pf neurons ( n = 52) rarely fired such bursts, but instead discharged groups of spikes at relatively low frequencies. The activity of CL and Pf neurons was often temporally coupled to cortical slow oscillations. Identified CL neurons possessed archetypal "bushy" dendrites and preferentially established synapses with dendritic spines (91% of synapses) of striatal projection neurons. Pf neurons possessed "reticular-like" dendrites, and, on average, preferentially established synapses with dendritic shafts (63%) in striatum, although connectivity was markedly heterogeneous across neurons. Two of the six Pf neurons studied exclusively targeted dendritic shafts, whereas another neuron almost exclusively (97%) targeted spines. The remaining three neurons preferentially targeted dendritic shafts ( 53 - 70%).Thus, the fundamental properties of CL and Pf neurons differ ( the latter do not express the typical operational principles of thalamic relay neurons), and they provide different temporally patterned inputs to distinct striatal targets. This mechanistic diversity likely underpins the transmission of specific and discrete information from intralaminar thalamic nuclei to striatal and cortical targets.