Levy Lucien M, Ziemann Ulf, Chen Robert, Cohen Leonardo G
Neuroimaging Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Building 10, 5D20, Bethesda, MD 20892, USA.
Ann Neurol. 2002 Dec;52(6):755-61. doi: 10.1002/ana.10372.
Recovery of function after acute injury to the central nervous system may be controlled by the availability of gamma-aminobutyric acid (GABA), the main inhibitory neurotransmitter in the cerebral cortex. Acute lesions as well as manipulation of sensory inputs can lead to rapid reorganization of the cerebral cortex, occurring within minutes to hours. Reduction of cortical inhibitory tone through a decrease in the availability of GABA has been suggested as a possible mechanism; however, the degree and temporal course of the changes in brain GABA are not known. A novel method using two-dimensional J-resolved magnetic resonance spectroscopy showed that GABA levels in the human sensorimotor cortex are quickly reduced within minutes of deafferentation. This finding strongly supports the view that the release of latent corticocortical projections from tonic inhibition through decreased GABA availability is a mechanism of rapid cortical plasticity. Reduction of brain GABA can play a pivotal role in regulating the extent of rapid cortical reorganization after lesions or changes in sensory input.
中枢神经系统急性损伤后的功能恢复可能受γ-氨基丁酸（GABA，大脑皮层主要的抑制性神经递质）可用性的控制。急性损伤以及感觉输入的操控可导致大脑皮层在数分钟到数小时内迅速重组。通过降低GABA可用性来降低皮层抑制张力被认为是一种可能的机制；然而，大脑GABA变化的程度和时间进程尚不清楚。一种使用二维J分辨磁共振波谱的新方法表明，在去传入神经支配后的数分钟内，人类感觉运动皮层中的GABA水平迅速降低。这一发现有力地支持了以下观点：通过降低GABA可用性从紧张性抑制中释放潜在的皮质-皮质投射是快速皮质可塑性的一种机制。大脑GABA的减少在调节损伤后或感觉输入变化后快速皮质重组的程度方面可能起关键作用。
