Limb-state information encoded by peripheral and central somatosensory neurons: implications for an afferent interface.
Limb-state information encoded by peripheral and central somatosensory neurons: implications for an afferent interface.
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DOI：
10.1109/tnsre.2011.2163145
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发表时间：
2011-10
期刊：
影响因子：
--
通讯作者：
Miller LE
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文献类型：
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作者：
Weber DJ;London BM;Hokanson JA;Ayers CA;Gaunt RA;Torres RR;Zaaimi B;Miller LE
一个主要的问题要解决的假肢控制的神经接口的发展是需要体感反馈。在这里，我们研究了两种可能的策略：电刺激背根神经节（DRG）或初级体感皮质（S1）。在每种方法中，我们必须确定一个模型，反映肢体状态的神经放电方面的代表性。然后，该模型可以用于设计刺激，人工激活神经系统，以向受试者传达有关肢体状态的信息。电激活DRG神经元使用自然的刺激模式，模仿被动肢体运动过程中的记录，诱发活动S1，这是类似于原来的运动。我们还发现，S1神经群体可以准确地区分不同模式的DRG刺激在很宽的刺激脉冲率。在研究S1神经元对肢体状态的编码过程中，我们还利用多电极记录对猴主动肢体运动的运动学进行了解码。具有本体感受野和皮肤感受野的神经元同样对这种解码做出了贡献。一些神经元在最近的过去是最能提供肢体状态的信息，但许多其他神经元似乎发出即将到来的运动信号，这表明它们也受到传出复制信号的调制。最后，我们表明，一只猴子能够检测到刺激，通过大比例的电极植入区域2。我们讨论了适当的刺激范式传达时变肢体状态信息的设计，以及中枢和外周方法的相对优点和局限性。
A major issue to be addressed in the development of neural interfaces for prosthetic control is the need for somatosensory feedback. Here, we investigate two possible strategies: electrical stimulation of either dorsal root ganglia (DRG) or primary somatosensory cortex (S1). In each approach, we must determine a model that reflects the representation of limb state in terms of neural discharge. This model can then be used to design stimuli that artificially activate the nervous system to convey information about limb state to the subject. Electrically activating DRG neurons using naturalistic stimulus patterns, modeled on recordings made during passive limb movement, evoked activity in S1 that was similar to that of the original movement. We also found that S1 neural populations could accurately discriminate different patterns of DRG stimulation across a wide range of stimulus pulse-rates. In studying the neural coding of limb-state in S1, we also decoded the kinematics of active limb movement using multi-electrode recordings in the monkey. Neurons having both proprioceptive and cutaneous receptive fields contributed equally to this decoding. Some neurons were most informative of limb state in the recent past, but many others appeared to signal upcoming movements suggesting that they also were modulated by an efference copy signal. Finally, we show that a monkey was able to detect stimulation through a large percentage of electrodes implanted in area 2. We discuss the design of appropriate stimulus paradigms for conveying time-varying limb state information, and the relative merits and limitations of central and peripheral approaches.