Neuronano Research Center, Department of Experimental Medicine, Lund University, Lund, Sweden.
Neuronano Research Center, Department of Experimental Medicine, Lund University, Lund, Sweden.
J Neurosci Methods. 2020 Sep 1;343:108842. doi: 10.1016/j.jneumeth.2020.108842. Epub 2020 Jul 3.
Reduction of insertion injury is likely important to approach physiological conditions in the vicinity of implanted devices intended to interface with the surrounding brain.
We have developed a novel, low-friction coating around frozen, gelatin embedded needles. By introducing a layer of thawing ice onto the gelatin, decreasing surface friction, we mitigate damage caused by the implantation.
The acute effects of a transient stab on neuronal density and glial reactions were assessed 1 and 7 days post stab in rat cortex and striatum both within and outside the insertion track using immunohistochemical staining. The addition of a coat of melting ice to the frozen gelatin embedded needles reduced the insertion force with around 50 %, substantially reduced the loss neurons (i.e. reduced neuronal void), and yielded near normal levels of astrocytes within the insertion track 1 day after insertion, as compared to gelatin coated probes of the same temperature without ice coating. There were negligible effects on glial reactions and neuronal density immediately outside the insertion track of both ice coated and cold gelatin embedded needles. This new method of implantation presents a considerable improvement compared to existing modes of device insertion.
Acute brain injuries following insertion of e.g. ultra-flexible electrodes, can be reduced by providing an outer coat of ultra-slippery thawing ice. No adverse effect of lowered implant temperature was found, opening the possibility of locking fragile electrode construct configurations in frozen gelatin, prior to implantation into the brain.
减少插入损伤可能对于接近植入设备与周围大脑接口的生理条件很重要。
我们开发了一种新型的、低摩擦涂层，用于冷冻的明胶包埋针周围。通过在明胶上引入一层解冻的冰，减少表面摩擦，我们减轻了植入物引起的损伤。
在大鼠皮层和纹状体中，通过免疫组织化学染色，评估了在插入轨迹内和外的 1 天和 7 天，短暂刺伤对神经元密度和神经胶质反应的急性影响。在冷冻的明胶包埋针上添加一层融化的冰，可将插入力降低约 50%，显著减少神经元的损失（即减少神经元空洞），并且在插入后 1 天，在插入轨迹内产生接近正常水平的星形胶质细胞，与没有冰涂层的相同温度的明胶涂层探针相比。冰涂层和冷明胶包埋针的插入轨迹外，对神经胶质反应和神经元密度几乎没有影响。与现有的设备插入模式相比，这种新的植入方法有了显著的改进。
例如，通过提供超光滑解冻冰的外部涂层，可以减少超灵活电极插入后的急性脑损伤。没有发现植入温度降低的不利影响，这为在将脆弱的电极结构锁定在冷冻明胶中之前将其植入大脑开辟了可能性。
