忘记了什么事吗？按下开关，向大脑发送一簇电信号，就能重建失去的记忆。美国科学家成功地在实验鼠身上实现了这种情景，这项新研究有望用于帮助脑部受损的人恢复基本的生活自理能力。

美国南加州大学的科学家报告说，他们在实验鼠脑部的海马区植入电极，训练它们进行一系列杠杆操作以获得奖励，并通过电极记录这一过程中实验鼠的脑部活动。

此前的研究曾表明，海马区能把短期记忆转换成长期记忆。科学家随后在实验鼠的海马区注入某种物质，阻断与长期记忆有关的神经信号。观察表明，这使实验鼠忘记了所受到的训练。

然而，当研究人员用电极向实验鼠脑部输入信号、模拟训练过程中的脑部活动时，实验鼠又暂时记起了正确的操作顺序。如果输入的是打乱过的信号，就没有这种效果。

科学家在新一期的《神经工程学期刊》发表论文说，希望今后能用这种方法向人类脑部输入信号，帮助早老痴呆症、中风或脑外伤患者恢复生活自理能力。不过，如何将人类生活中的简单日常事务编成正确的代码，将是一项艰巨的挑战。

原文出处：

Journal of Neural Engineering    DOI： 10.1088/1741-2560/8/4/046017

A cortical neural prosthesis for restoring and enhancing memory

Berger, Theodore W; Hampson, Robert E; Song, Dong; Goonawardena, Anushka; Marmarelis, Vasilis Z; Deadwyler, Sam A

A primary objective in developing a neural prosthesis is to replace neural circuitry in the brain that no longer functions appropriately. Such a goal requires artificial reconstruction of neuron-to-neuron connections in a way that can be recognized by the remaining normal circuitry, and that promotes appropriate interaction. In this study, the application of a specially designed neural prosthesis using a multi-input/multi-output (MIMO) nonlinear model is demonstrated by using trains of electrical stimulation pulses to substitute for MIMO model derived ensemble firing patterns. Ensembles of CA3 and CA1 hippocampal neurons, recorded from rats performing a delayed-nonmatch-to-sample (DNMS) memory task, exhibited successful encoding of trial-specific sample lever information in the form of different spatiotemporal firing patterns. MIMO patterns, identified online and in real-time, were employed within a closed-loop behavioral paradigm. Results showed that the model was able to predict successful performance on the same trial. Also, MIMO model-derived patterns, delivered as electrical stimulation to the same electrodes, improved performance under normal testing conditions and, more importantly, were capable of recovering performance when delivered to animals with ensemble hippocampal activity compromised by pharmacologic blockade of synaptic transmission. These integrated experimental-modeling studies show for the first time that, with sufficient information about the neural coding of memories, a neural prosthesis capable of real-time diagnosis and manipulation of the encoding process can restore and even enhance cognitive, mnemonic processes.PACS87.80.-y Biophysical techniques (research methods)