Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX2 6GG, UK.
Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX2 6GG, UK.
Cell Rep. 2022 Jun 14;39(11):110951. doi: 10.1016/j.celrep.2022.110951.
Synaptic plasticity is required for learning and follows Hebb's rule, the computational principle underpinning associative learning. In recent years, a complementary type of brain plasticity has been identified in myelinated axons, which make up the majority of brain's white matter. Like synaptic plasticity, myelin plasticity is required for learning, but it is unclear whether it is Hebbian or whether it follows different rules. Here, we provide evidence that white matter plasticity operates following Hebb's rule in humans. Across two experiments, we find that co-stimulating cortical areas to induce Hebbian plasticity leads to relative increases in cortical excitability and associated increases in a myelin marker within the stimulated fiber bundle. We conclude that Hebbian plasticity extends beyond synaptic changes and can be observed in human white matter fibers.
突触可塑性是学习所必需的，遵循赫布定律，这是联想学习的基础计算原理。近年来，在构成大脑大部分白质的髓鞘轴突中发现了一种互补的脑可塑性。像突触可塑性一样，髓鞘可塑性是学习所必需的，但尚不清楚它是否遵循赫布定律，或者是否遵循不同的规则。在这里，我们提供的证据表明，人类的白质可塑性是遵循赫布定律的。在两项实验中，我们发现，刺激皮层区域以诱导赫布可塑性会导致皮层兴奋性相对增加，并在被刺激的纤维束内相应增加髓鞘标记物。我们的结论是，赫布可塑性不仅限于突触变化，而且可以在人类白质纤维中观察到。
