Gordon Stephen G, Sacco Alessandra, Lomber Stephen G
Integrated Program in Neuroscience, McGill University, Montreal, Canada.
Department of Physiology, Faculty of Medicine and Health Sciences, McGill University, Montreal, Canada.
Neuroimage Rep. 2024 Jul 3;4(3):100213. doi: 10.1016/j.ynirp.2024.100213. eCollection 2024 Sep.
In the absence of hearing, the plastic nature of the cerebral cortex allows select regions to be repurposed to serve the processing of remaining sensory modalities. This plasticity can be observed in many ways, including measuring the thickness differences of cortical gray matter between hearing and deaf populations to detect regional adaptations. In this study, T1-weighted images were acquired for hearing (n = 38) and perinatally-deafened (n = 31) cats using an ultra-high field 7T MRI scanner to identify normative feline cortical thickness, as well as areas of differing thickness between groups. Most significant changes to sensory-related regions demonstrated thicker cortices in the deaf compared to the hearing group, while specific non-sensory regions were found to be thinner. Furthermore, there was a modest lateralized component, finding that the gray matter of the left hemisphere was more susceptible to thickness changes following auditory deprivation. These results suggest distinct factors driving the adaptations in sensory versus non-sensory cortices in the brain following deafness, and reinforces the task-retainment model of crossmodal plasticity.
在听力缺失的情况下，大脑皮层的可塑性使得特定区域能够被重新利用，以处理剩余的感觉模态。这种可塑性可以通过多种方式观察到，包括测量听力正常和失聪人群之间皮质灰质的厚度差异，以检测区域适应性。在本研究中，使用超高场7T MRI扫描仪对听力正常的猫（n = 38）和出生时即致聋的猫（n = 31）采集T1加权图像，以确定正常猫的皮质厚度以及两组之间厚度不同的区域。与感觉相关区域的最显著变化表明，与听力正常组相比，失聪组的皮质更厚，而特定的非感觉区域则更薄。此外，存在适度的偏侧化成分，发现左半球的灰质在听觉剥夺后更容易发生厚度变化。这些结果表明，耳聋后大脑中感觉皮层和非感觉皮层适应性变化的驱动因素不同，并强化了跨模态可塑性的任务保留模型。
