Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Nobels väg 9, 171 77, Stockholm, Sweden.
Department of Otorhinolaryngology, Smell and Taste Clinic, TU Dresden, Dresden, Germany.
Sci Rep. 2021 Aug 12;11(1):16422. doi: 10.1038/s41598-021-95968-7.
Removing function from a developed and functional sensory system is known to alter both cerebral morphology and functional connections. To date, a majority of studies assessing sensory-dependent plasticity have focused on effects from either early onset or long-term sensory loss and little is known how the recent sensory loss affects the human brain. With the aim of determining how recent sensory loss affects cerebral morphology and functional connectivity, we assessed differences between individuals with acquired olfactory loss (duration 7-36 months) and matched healthy controls in their grey matter volume, using multivariate pattern analyses, and functional connectivity, using dynamic connectivity analyses, within and from the olfactory cortex. Our results demonstrate that acquired olfactory loss is associated with altered grey matter volume in, among others, posterior piriform cortex, a core olfactory processing area, as well as the inferior frontal gyrus and angular gyrus. In addition, compared to controls, individuals with acquired anosmia displayed significantly stronger dynamic functional connectivity from the posterior piriform cortex to, among others, the angular gyrus, a known multisensory integration area. When assessing differences in dynamic functional connectivity from the angular gyrus, individuals with acquired anosmia had stronger connectivity from the angular gyrus to areas primary responsible for basic visual processing. These results demonstrate that recently acquired sensory loss is associated with both changed cerebral morphology within core olfactory areas and increase dynamic functional connectivity from olfactory cortex to cerebral areas processing multisensory integration.
已知，从一个发育良好且功能正常的感觉系统中去除功能会改变大脑形态和功能连接。迄今为止，大多数评估感觉依赖性可塑性的研究都集中在早期发病或长期感觉丧失的影响上，而对于最近的感觉丧失如何影响人类大脑知之甚少。为了确定最近的感觉丧失如何影响大脑形态和功能连接，我们使用多元模式分析评估了具有获得性嗅觉丧失（持续时间 7-36 个月）的个体与匹配的健康对照组之间的灰质体积差异，使用动态连接分析评估了嗅觉皮层内和来自嗅觉皮层的功能连接。我们的结果表明，获得性嗅觉丧失与后梨状皮质等核心嗅觉处理区域以及额下回和角回等区域的灰质体积改变有关。此外，与对照组相比，获得性嗅觉丧失的个体表现出后梨状皮质与角回等区域之间的动态功能连接显著增强，角回是一个已知的多感觉整合区域。当评估来自角回的动态功能连接差异时，获得性嗅觉丧失的个体表现出更强的连接，来自角回的连接来自主要负责基本视觉处理的区域。这些结果表明，最近获得的感觉丧失与核心嗅觉区域内的大脑形态变化以及嗅觉皮层到处理多感觉整合的大脑区域的动态功能连接增强有关。
