Pavlova Elena, Hedberg Åsa, Ponten Eva, Gantelius Stefan, Valero-Cuevas Francisco J, Forssberg Hans
Department of Rehabilitation Medicine, Danderyd University Hospital, 18288 Stockholm, Sweden; Department of Clinical Sciences, Karolinska Institute, 18288 Stockholm, Sweden.
Department of Women׳s and Children׳s Health, Neuropediatric Research Unit, Karolinska Institute, 17176 Stockholm, Sweden; Stockholm Brain Institute, Karolinska Institute, 17176 Stockholm, Sweden.
Brain Res. 2015 Sep 16;1620:98-106. doi: 10.1016/j.brainres.2015.05.016. Epub 2015 May 19.
To study whether a temporary block of the tactile afferents from the fingers causes altered activity in the neural network for dexterous manipulation.
Whole-brain functional Magnetic Resonance Imaging (fMRI) was conducted in 18 healthy subjects, while they compressed an unstable spring between the thumb and index finger of the right hand. Two sensory conditions--with and without tactile input from the fingers--were employed. In the latter condition the digital nerves were blocked by local anesthesia.
Compression of the unstable spring was associated with activity in an earlier described network for object manipulation. We found that this entire network remained active after a nerve block, and the activity was increased in the dorsal premotor cortex.
The neural network for dexterous manipulation is robust with only minor alterations after acute loss of tactile information from the fingers. There was no loss of activity, but, unexpectedly, an increased activity in some parts of the network.
This study gives new insights to possible neural compensatory mechanisms that make fine motor control possible after acute disruption of tactile information in natural situations like cold weather or wearing surgical gloves.
研究手指触觉传入神经的暂时阻断是否会改变灵巧操作神经网络的活动。
对18名健康受试者进行全脑功能磁共振成像（fMRI），同时他们用右手拇指和食指挤压一个不稳定的弹簧。采用两种感觉条件——有和没有来自手指的触觉输入。在后一种条件下，通过局部麻醉阻断指神经。
挤压不稳定弹簧与先前描述的物体操作网络的活动相关。我们发现，神经阻断后整个网络仍保持活跃，且背侧运动前皮层的活动增强。
灵巧操作的神经网络具有很强的鲁棒性，在手指触觉信息急性丧失后仅有轻微改变。没有活动丧失，但出乎意料的是，网络某些部分的活动增加。
本研究为在寒冷天气或戴手术手套等自然情况下触觉信息急性中断后使精细运动控制成为可能的潜在神经补偿机制提供了新的见解。
