Neuronal Circuit Remodeling in the Contralateral Cortical Hemisphere during Functional Recovery from Cerebral Infarction
Neuronal Circuit Remodeling in the Contralateral Cortical Hemisphere during Functional Recovery from Cerebral Infarction
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DOI：
10.1523/jneurosci.1638-09.2009
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发表时间：
2009-08-12
影响因子：
5.3
通讯作者：
Nabekura, Junichi
中科院分区：
文献类型：
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作者：
Takatsuru, Yusuke;Fukumoto, Dai;Nabekura, Junichi
卒中患者脑功能成像的最新进展，如功能磁共振成像，揭示了脑梗塞对侧大脑皮质在脑功能恢复过程中的重要作用。然而，在功能恢复过程中发生在对侧大脑半球的潜在机制尚未阐明。我们在实验上诱导了小鼠右半球躯体感觉皮质的完全性脑梗塞，并观察了恢复期对侧(左侧)躯体感觉皮层神经元的变化。用双光子成像技术观察到，在卒中后2天，左侧(完整)半球的基础和同侧躯体感觉刺激诱发的神经元活动均一过性增加，随后在1周时通常稳定的蘑菇型突触棘的翻转率增加。在卒中后4周，当功能恢复时，在完整的同侧大脑半球建立了一种对躯体感觉刺激做出反应的新的电路活动模式。因此，左侧躯体感觉皮层可以通过重塑神经元回路和建立新的感觉加工来补偿右侧躯体感觉皮质的丧失。这一发现可能有助于建立针对完整大脑半球的有效临床治疗方法，以恢复受损的功能，并实现更好的患者生活质量。
Recent advances in functional imaging of human brain activity in stroke patients, e.g., functional magnetic resonance imaging, have revealed that cortical hemisphere contralateral to the infarction plays an important role in the recovery process. However, underlying mechanisms occurring in contralateral hemisphere during functional recovery have not been elucidated. We experimentally induced a complete infarction of somatosensory cortex in right hemisphere of mice and examined the neuronal changes in contralateral (left) somatosensory cortex during recovery. Both basal and ipsilateral somatosensory stimuli-evoked neuronal activity in left (intact) hemisphere transiently increased 2 d after stroke, followed by an increase in the turnover rate of usually stable mushroom-type synaptic spines at 1 week, observed by using two-photon imaging in vivo. At 4 weeks after stroke, when functional recovery had occurred, a new pattern of electrical circuit activity in response to somatosensory stimuli was established in intact ipsilateral hemisphere. Thus, the left somatosensory cortex can compensate for the loss of the right somatosensory cortex by remodeling neuronal circuits and establishing new sensory processing. This finding could contribute to establish the effective clinical treatments targeted on the intact hemisphere for the recovery of impaired functions and to achieve better quality of life of patients.