Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital at Linkou, Taoyuan City, Taiwan.
School of Medicine, Chang Gung University, Taoyuan City, Taiwan.
Restor Neurol Neurosci. 2019;37(4):409-419. doi: 10.3233/RNN-190914.
Nerve reconstructive surgery induces a transient loss and a prolonged and a gradual return of sensory inputs to the brain. It is unknown whether, following this massive peripheral denervation, the brain will experience a prolonged period of severe, intrinsic dysfunction.
We aim to investigate the mechanisms of return of processing function in cortical neurons.
We used the whisker model in rats to evaluate the functional recovery in the somatosensory cortex after a nerve reconstruction surgery. Multi-unit recording in the barrel cortex was performed in lightly anesthetized rats while their whiskers were stimulated by a whisker stimulator.
We observed a loss of neuronal responses to whisker stimulation 1 week after surgery, which started to recover 2 weeks after surgery. Following the surgery, only 11.8% of units had principle whiskers (PWs) returned to their original status while 17.7% had PWs different from their original status, indicating the effect of aberrant reinnervation on the whisker response map.
Robust neuronal responses to sensory stimulation even when only sparse sensory inputs are available in the early recovery phase. During this phase, aberrant reinnervation induces disorganized whisker tuning, a finding that might be account for the hypoesthesia and paresthesia during early recovery after nerve reconstruction.
神经重建手术后，大脑会经历短暂的感觉输入丧失，以及长时间的逐渐恢复。目前尚不清楚在经历这种大规模外周神经去神经支配后，大脑是否会经历长时间的严重内在功能障碍。
我们旨在研究皮质神经元处理功能恢复的机制。
我们使用大鼠的胡须模型来评估神经重建手术后感觉皮层的功能恢复情况。在轻度麻醉的大鼠中，当他们的胡须被胡须刺激器刺激时，我们在其皮层进行多单位记录。
我们观察到手术后 1 周神经元对胡须刺激的反应丧失，2 周后开始恢复。手术后，只有 11.8%的单位的主要胡须（PW）恢复到原来的状态，而 17.7%的单位的 PW 与原来的状态不同，这表明异常再神经支配对胡须反应图的影响。
即使在早期恢复阶段只有稀疏的感觉输入，也能产生强烈的感觉刺激反应。在这个阶段，异常再神经支配会导致胡须调谐紊乱，这一发现可能解释了神经重建后早期恢复期间的感觉迟钝和感觉异常。
