Evidence for layer-specific differences in auditory corticocollicular neurons.
Evidence for layer-specific differences in auditory corticocollicular neurons.
复制标题
听觉皮质神经元层特异性差异的证据。
DOI：
10.1016/j.neuroscience.2012.10.053
复制
发表时间：
2013
期刊：
影响因子：
3.3
通讯作者：
Llano,DA
中科院分区：
文献类型：
--
作者：
Slater,BJ;Willis,AM;Llano,DA
最近的数据表明，可能有不同的处理流从听觉皮层层5和6影响听觉中脑。为了确定这些投射是否具有不同的生理特性，我们将罗丹明标记的乳胶示踪珠注射到>30日龄小鼠的下丘中以标记这些离皮质细胞。对62个标记的细胞进行全细胞记录以确定其基本电生理特性，并用生物胞素填充细胞以确定其形态学特征。第5层听觉皮质丘细胞具有突出的Ih介导的凹陷和反弹电流，具有相对缓慢的时间常数，并能产生钙依赖性节律爆发。与此相反，第6层听觉皮质丘细胞是非爆裂，不表现出下垂或反弹电流，并具有短的时间常数。形态学定量分析显示第6层细胞较小，具有水平取向，并且具有非常长的树突（>500μm），其分支丰富，均位于软脑膜远端附近的索马附近。第5层皮质丘细胞为大型锥体细胞，顶端有长树突，在软膜表面附近分支最多。第5层和第6层神经元之间的生理特性和树突分支的显着差异使得每种类型在控制中脑的听觉信息处理中起着不同的作用。
Recent data suggest that there may be distinct processing streams emanating from auditory cortical layers 5 and 6 that influence the auditory midbrain. To determine whether these projections have different physiological properties, we injected rhodamine-tagged latex tracer beads into the inferior colliculus of >30-day-old mice to label these corticofugal cells. Whole-cell recordings were performed on 62 labeled cells to determine their basic electrophysiological properties and cells were filled with biocytin to determine their morphological characteristics. Layer 5 auditory corticocollicular cells have prominent Ih-mediated sag and rebound currents, have relatively sluggish time constants, and can generate calcium-dependent rhythmic bursts. In contrast, layer 6 auditory corticocollicular cells are non-bursting, do not demonstrate sag or rebound currents and have short time constants. Quantitative analysis of morphology showed that layer 6 cells are smaller, have a horizontal orientation, and have very long dendrites (>500μm) that branch profusely both near the soma distally near the pia. Layer 5 corticocollicular cells are large pyramidal cells with a long apical dendrite with most branching near the pial surface. The marked differences in physiological properties and dendritic arborization between neurons in layers 5 and 6 make it likely that each type plays a distinct role in controlling auditory information processing in the midbrain.