Computation in Neural Circuits Group, Max Planck Institute for Brain Research, Frankfurt, Germany.
School of Life Sciences, Technical University of Munich, Freising, Germany.
Nat Commun. 2021 Jun 28;12(1):4005. doi: 10.1038/s41467-021-23557-3.
Synaptic inputs on cortical dendrites are organized with remarkable subcellular precision at the micron level. This organization emerges during early postnatal development through patterned spontaneous activity and manifests both locally where nearby synapses are significantly correlated, and globally with distance to the soma. We propose a biophysically motivated synaptic plasticity model to dissect the mechanistic origins of this organization during development and elucidate synaptic clustering of different stimulus features in the adult. Our model captures local clustering of orientation in ferret and receptive field overlap in mouse visual cortex based on the receptive field diameter and the cortical magnification of visual space. Including action potential back-propagation explains branch clustering heterogeneity in the ferret and produces a global retinotopy gradient from soma to dendrite in the mouse. Therefore, by combining activity-dependent synaptic competition and species-specific receptive fields, our framework explains different aspects of synaptic organization regarding stimulus features and spatial scales.
皮质树突上的突触输入在微米水平上具有显著的亚细胞精度组织。这种组织通过模式化的自发活动在出生后早期发育中出现，并表现出局部的相关性，即附近的突触显著相关，以及全局的与距离胞体的相关性。我们提出了一个基于生物物理的突触可塑性模型，以剖析发育过程中这种组织的机制起源，并阐明成年后不同刺激特征的突触聚类。我们的模型基于感受野直径和视觉空间的皮质放大，捕捉了雪貂视皮层中方向的局部聚类和小鼠视觉皮层中感受野的重叠。包括动作电位反向传播解释了雪貂中分支聚类的异质性，并在小鼠中产生了从胞体到树突的全局视网膜拓扑梯度。因此，通过结合活动依赖性突触竞争和物种特异性感受野，我们的框架解释了关于刺激特征和空间尺度的不同方面的突触组织。
