McPherson Jacob Graves, Bandres Maria F
Program in Physical Therapy, Washington University School of Medicine, St. Louis, United States.
Department of Anesthesiology, Washington University School of Medicine, St. Louis, United States.
Elife. 2021 May 27;10:e66308. doi: 10.7554/eLife.66308.
Non-random functional connectivity during unconsciousness is a defining feature of supraspinal networks. However, its generalizability to intrinsic spinal networks remains incompletely understood. Previously, Barry et al., 2014 used fMRI to reveal bilateral resting state functional connectivity within sensory-dominant and, separately, motor-dominant regions of the spinal cord. Here, we record spike trains from large populations of spinal interneurons in vivo in rats and demonstrate that spontaneous functional connectivity also links sensory- and motor-dominant regions during unconsciousness. The spatiotemporal patterns of connectivity could not be explained by latent afferent activity or by populations of interconnected neurons spiking randomly. We also document connection latencies compatible with mono- and disynaptic interactions and putative excitatory and inhibitory connections. The observed activity is consistent with the hypothesis that salient, experience-dependent patterns of neural transmission introduced during behavior or by injury/disease are reactivated during unconsciousness. Such a spinal replay mechanism could shape circuit-level connectivity and ultimately behavior.
无意识状态下的非随机功能连接是脊髓上网络的一个决定性特征。然而，其对内在脊髓网络的普遍性仍未完全理解。此前，巴里等人在2014年使用功能磁共振成像来揭示脊髓感觉主导区和运动主导区各自的双侧静息态功能连接。在这里，我们在大鼠体内记录了大量脊髓中间神经元的动作电位序列，并证明在无意识状态下，自发功能连接也连接着感觉主导区和运动主导区。连接的时空模式无法用潜在传入活动或相互连接的神经元群体随机发放来解释。我们还记录了与单突触和双突触相互作用以及假定的兴奋性和抑制性连接相匹配的连接潜伏期。观察到的活动与以下假设一致：在行为期间或因损伤/疾病引入的显著的、依赖经验的神经传递模式在无意识状态下被重新激活。这种脊髓重放机制可能塑造电路水平的连接并最终影响行为。
