Macro-connectomics and microstructure predict dynamic plasticity patterns in the non-human primate brain.
Macro-connectomics and microstructure predict dynamic plasticity patterns in the non-human primate brain.
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DOI：
10.7554/elife.34354
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发表时间：
2018-11-21
期刊：
影响因子：
7.7
通讯作者：
Croxson PL
中科院分区：
文献类型：
--
作者：
Froudist-Walsh S;Browning PG;Young JJ;Murphy KL;Mars RB;Fleysher L;Croxson PL
大脑显示出非凡的能力，通过神经可塑性改变其连接来适应损伤。许多可塑性背后的生物学机制是已知的，但对于损伤后大脑中何时或何处发生可塑性却知之甚少。这些知识可以指导促进可塑性的干预措施，并为受伤后的恢复过程创建更准确的路线图。我们因果关系研究了可塑性的时间过程后，海马病变，使用多模态MRI在猴子。我们发现，损伤后的可塑性是高度动态的，但在很大程度上是可预测的基础上的功能连接的病变区域，梯度的细胞密度在整个皮层和病变前的网络结构的大脑。预测哪些大脑区域在受伤后将可塑性地适应其功能连接的能力可能使我们能够解释为什么一些大脑损伤会导致认知功能的永久丧失，而其他人则不会。大脑有能力在受伤后适应，这一过程被称为可塑性。当一个区域受到损害时，例如车祸或中风，其他区域会改变它们的活动和结构来补偿。了解这种情况是如何发生的，对于帮助人们从脑损伤中恢复至关重要。某些因素可能会影响大脑的自我修复能力。这些包括受损区域与其他区域相互作用的程度，以及大脑不同区域包含哪些细胞类型。Froudist-Walsh等人着手确定这些因素如何影响猴子脑损伤的恢复，猴子的大脑与我们的大脑相似。猴子的海马体结构受损。大脑的这一部分在记忆中起着关键作用，而记忆在脑损伤患者中往往会受损。海马体不能自我修复，因为大脑生长新神经元的能力有限。相反，大脑试图通过其他未受损区域的变化来补偿海马体的破坏。Froudist-Walsh等人利用脑成像技术表明，发生的变化类型取决于受伤后的时间。在最初的三个月里，大脑的许多区域改变了它们与其他区域协调活动的程度。高度连接的区域减少了他们与其他区域的沟通。从长远来看，大脑区域的反应更多地取决于它们所包含的细胞类型。有更多支持细胞的区域被称为“神经胶质”-为神经元提供营养和能量-能够在受伤后一年内更好地适应它们的连接。这些发现可能最终使那些在事故或中风后遭受脑损伤的人受益。他们认为，刺激完整的大脑区域可能在受伤后的几个月内有所帮助。相比之下，长期治疗可能需要更多地关注结构修复。未来的研究必须建立在这些结果的基础上，以发现诱导脑损伤成功恢复的最佳方法。
The brain displays a remarkable ability to adapt following injury by altering its connections through neural plasticity. Many of the biological mechanisms that underlie plasticity are known, but there is little knowledge as to when, or where in the brain plasticity will occur following injury. This knowledge could guide plasticity-promoting interventions and create a more accurate roadmap of the recovery process following injury. We causally investigated the time-course of plasticity after hippocampal lesions using multi-modal MRI in monkeys. We show that post-injury plasticity is highly dynamic, but also largely predictable on the basis of the functional connectivity of the lesioned region, gradients of cell densities across the cortex and the pre-lesion network structure of the brain. The ability to predict which brain areas will plastically adapt their functional connectivity following injury may allow us to decipher why some brain lesions lead to permanent loss of cognitive function, while others do not. The brain has the ability to adapt after injury, a process known as plasticity. When one area sustains damage, for example following a car accident or stroke, other areas change their activity and structure to compensate. Understanding how this happens is critical to helping people recover from brain injuries. Certain factors may affect how well the brain can repair itself. These include how much the damaged area interacts with other areas, and which cell types different areas of the brain contain. Froudist-Walsh et al. set out to determine how these factors influence recovery from brain injury in monkeys, whose brains are similar to our own. The monkeys had damage to a structure called the hippocampus. This part of the brain has a key role in memory, which is often impaired in patients with brain injuries. The hippocampus cannot repair itself because the brain has only a limited capacity to grow new neurons. Instead, the brain attempts to compensate for disruption to the hippocampus via changes in other, undamaged areas. Using brain imaging, Froudist-Walsh et al. show that the types of changes that occur depend on how much time has passed since the injury. In the first three months, many areas of the brain change how much they coordinate their activity with other areas. Highly connected areas reduce their communication with other areas the most. In the long-term, the responses of brain areas depend more on which cell types they contain. Areas with more support cells known as “glia” – which supply nutrients and energy to neurons – are better able to adapt their connectivity up to a year after the injury. These findings may ultimately benefit people who have suffered brain injuries after accidents or stroke. They suggest that stimulating intact brain areas may be helpful in the months immediately after an injury. By contrast, long-term therapy may need to focus more on structural repair. Future studies must build on these results to discover the best ways to induce successful recovery from brain injury.