Nucleus reuniens of the thalamus contains head direction cells.
Nucleus reuniens of the thalamus contains head direction cells.
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DOI：
10.7554/elife.03075
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发表时间：
2014-07-14
期刊：
影响因子：
7.7
通讯作者：
O'Mara SM
中科院分区：
文献类型：
--
作者：
Jankowski MM;Islam MN;Wright NF;Vann SD;Erichsen JT;Aggleton JP;O'Mara SM
离散的脑细胞群体发出方向信号，就像指南针一样。这些“头部方向”细胞在很大程度上局限于一个紧密连接的网站网络。我们描述，第一次，在自由移动的大鼠丘脑的核reuniens的头方向细胞的人口。这种新的皮层下头部方向信号可能直接调制海马CA场，从而通知空间处理和记忆。http://dx.doi.org/10.7554/eLife.03075.001无论是觅食还是寻找回巢的路，动物都需要知道自己的前进方向。哺乳动物大脑中的一些神经元已经被证明像指南针一样起作用，每当动物将头指向某个方向时，就会发出神经脉冲。例如，当动物面向东北时，其中一些神经元会被激发，但当它面向西北时则不会，反之亦然。重要的是，这些被称为“头部方向”细胞的神经元实际上并不测量地球的磁场。相反，它们会对环境中的地标信息以及动物头部或身体的运动做出反应，以确定动物正面向哪个方向。头部方向细胞主要存在于大脑中几个位置的紧密连接网络中。然而，Jankowski等人现在在大脑中心深处的另一个区域发现了更多的这些细胞。在一个测试竞技场周围自由移动的大鼠中，测量这些神经元的神经冲动显示，这些神经元的放电方式与大脑其他区域的其他头部方向细胞完全相同。例如，当老鼠面向一个方向时，他们就开枪，但当它转过头面向另一个方向时，他们就停止开枪。Jankowski等人的研究表明，当测试竞技场中的灯光关闭时，或者当竞技场的形状从圆形变成正方形时，大脑这一区域的头部方向细胞继续工作。当大鼠进入测试竞技场时，这些神经元就开始发送有关头部方向的信息，并且当大鼠面向同一方向时，即使在不同的几天重新测试，许多神经元也会继续放电。Jankowski等人发现的头部方向细胞连接到大脑的另一个区域，该区域参与记忆环境中的不同位置并在它们之间导航。这表明这些神经元可能提供执行这些任务所需的一些信息。这也意味着，大脑中靠近接收外界输入的区域可能会执行比以前认为的更复杂的认知功能。DOI：http://dx.doi.org/10.7554/eLife.03075.002网站
Discrete populations of brain cells signal heading direction, rather like a compass. These ‘head direction’ cells are largely confined to a closely-connected network of sites. We describe, for the first time, a population of head direction cells in nucleus reuniens of the thalamus in the freely-moving rat. This novel subcortical head direction signal potentially modulates the hippocampal CA fields directly and, thus, informs spatial processing and memory. DOI: http://dx.doi.org/10.7554/eLife.03075.001 Whether it is foraging for food or finding its way back to its nest, an animal often needs to know which direction it is heading in. Some neurons in a mammal’s brain have been shown to act like a compass, and send out nerve impulses whenever the animal points its head in a certain direction. For example, some of these neurons will fire when the animal faces northeast, but not when it faces northwest, and vice versa. Importantly these neurons, called ‘head direction’ cells, do not actually measure the Earth's magnetic field. Rather, they respond to information about landmarks in the environment and the animal's movements of its head or body to work out which way the animal is facing. Head direction cells are largely found in a closely-connected network of a few sites in the brain. However, Jankowski et al. have now discovered more of these cells in another region found deep within the centre of the brain. Measuring the nerve impulses from these neurons in rats that were moving freely around a test arena revealed that the neurons fired in exactly the same way as some other head direction cells in other regions of the brain. For example, they fired whenever the rat faced one direction, but stopped firing when it turned its head to face another. Jankowski et al. showed that the head direction cells in this region of the brain continued to work when the lights were turned off in the test arena, or when the shape of the arena was changed from a circle to a square. These neurons began sending information about head direction as soon as the rat entered the test arena, and many continued to fire when the rat faced the same direction even when they were retested on several different days. The head direction cells discovered by Jankowski et al. are connected to another region of the brain that is involved in remembering different locations in the environment and navigating between them. This suggests that these neurons might provide some of the information required to carry out these tasks. It also means that areas of the brain close to those that receive input from the outside world may perform more complex cognitive functions than previously thought. DOI: http://dx.doi.org/10.7554/eLife.03075.002