Sensory experience remodels neural circuits in the early postnatal brain through mechanisms that remain to be elucidated. Applying a new method of ultrastructural analysis to the retinogeniculate circuit, we find that visual experience alters the number and structure of synapses between the retina and the thalamus. These changes require vision-dependent transcription of the receptor Fn14 in thalamic relay neurons and the induction of its ligand TWEAK in microglia. Fn14 functions to increase the number of bulbous spine-associated synapses at retinogeniculate connections, likely contributing to the strengthening of the circuit that occurs in response to visual experience. However, at retinogeniculate connections near TWEAK-expressing microglia, TWEAK signals via Fn14 to restrict the number of bulbous spines on relay neurons, leading to the elimination of a subset of connections. Thus, TWEAK and Fn14 represent an intercellular signaling axis through which microglia shape retinogeniculate connectivity in response to sensory experience.

感官体验通过仍有待阐明的机制重塑出生后早期大脑中的神经回路。将一种新的超微结构分析方法应用于视网膜原性回路，我们发现视觉体验会改变视网膜和丘脑之间突触的数量和结构。这些变化需要丘脑中继神经元中受体 Fn14 的视觉依赖性转录以及小胶质细胞中其配体 TWEAK 的诱导。Fn14 的功能是增加视网膜原性连接处球根状脊柱相关突触的数量，这可能有助于加强响应视觉体验的回路。然而，在表达 TWEAK 的小胶质细胞附近的视网膜连接处，TWEAK 通过 Fn14 发出信号以限制中继神经元上球状棘的数量，导致消除连接的子集。因此，TWEAK 和 Fn14 代表了一个细胞间信号轴，小胶质细胞通过该轴形成视网膜生成连接以响应感官体验。