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. 2025 Feb 8;5(1):100239. doi: 10.1016/j.ynirp.2025.100239. eCollection 2025 Mar.
The overall function and associated structure of the brain changes dramatically following early-onset hearing loss in a process known as compensatory crossmodal plasticity. As the microscale changes to cerebral morphology driving these adaptations can be reflected macrostructurally in MRI analyses, high interregional correlations in features such as gray matter thickness are potentially indicative of functional relationships. To probe the changes in these associations following deafness using structure alone, perinatally-deafened and hearing control cats were scanned at 7T to obtain high-resolution T1-weighted images. After calculating regional thicknesses for 146 cortical areas, the 10,585 associated pairwise correlations were used to establish group-specific structural connectomes. Similar distributions of correlation strength were revealed between the two populations, however there was an overall increase in the density of the structurally-defined connectome following deafness. The connections demonstrating the most dramatic increases of correlational strength in the deprived group were those relating to the auditory and visual cortices, with a more balanced distribution of increases and decreases to connections involving solely non-sensory regions. In corroboration with previous feline structural- and diffusion-based neuroimaging literature, these results imply a reorganization of cortical gray matter to increase the overall processing of the remaining senses within a potentially less complex and more redundant connectome. The present study adds to the developing field of deafness literature through the implementation of novel analyses that add an additional perspective on neuroplasticity within the feline brain.
在一个被称为代偿性跨模态可塑性的过程中，早发性听力损失后大脑的整体功能和相关结构会发生巨大变化。由于驱动这些适应性变化的大脑形态学微观尺度变化在MRI分析中可以在宏观结构上得到反映，灰质厚度等特征的高区域间相关性可能表明功能关系。为了仅使用结构来探究耳聋后这些关联的变化，对围产期致聋的猫和听力正常的对照猫进行了7T扫描，以获得高分辨率T1加权图像。在计算了146个皮质区域的区域厚度后，使用10585个相关的成对相关性来建立特定组的结构连接组。两组之间揭示了相似的相关强度分布，然而耳聋后结构定义的连接组密度总体上有所增加。在剥夺组中相关性强度增加最显著的连接是与听觉和视觉皮层相关的连接，而仅涉及非感觉区域的连接增加和减少的分布更为平衡。与先前基于猫的结构和扩散的神经影像学文献一致，这些结果意味着皮质灰质的重组，以在潜在更简单和更冗余的连接组内增加对其余感觉的整体处理。本研究通过实施新颖的分析，为耳聋文献这一不断发展的领域增添了内容，这些分析为猫脑内的神经可塑性提供了一个额外的视角。
