The mouse cerebral cortex contains neurons that express choline acetyltransferase (ChAT) and are a potential local source of acetylcholine. However, the neurotransmitters released by cortical ChAT+ neurons and their synaptic connectivity are unknown. We show that the nearly all cortical ChAT+ neurons in mice are specialized VIP+ interneurons that release GABA strongly onto other inhibitory interneurons and acetylcholine sparsely onto layer 1 interneurons and other VIP+/ChAT+ interneurons. This differential transmission of ACh and GABA based on the postsynaptic target neuron is reflected in VIP+/ChAT+ interneuron pre-synaptic terminals, as quantitative molecular analysis shows that only a subset of these are specialized to release acetylcholine. In addition, we identify a separate, sparse population of non-VIP ChAT+ neurons in the medial prefrontal cortex with a distinct developmental origin that robustly release acetylcholine in layer 1. These results demonstrate both cortex-region heterogeneity in cortical ChAT+ interneurons and target-specific co-release of acetylcholine and GABA.

中文翻译：

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皮质 ChAT+ 神经元以靶区和脑区特异性方式共同传输乙酰胆碱和 GABA

小鼠大脑皮层含有表达胆碱乙酰转移酶 (ChAT) 的神经元，是乙酰胆碱的潜在局部来源。然而，皮质 ChAT+ 神经元释放的神经递质及其突触连接是未知的。我们表明，小鼠中几乎所有的皮质 ChAT+ 神经元都是专门的 VIP+ 中间神经元，它们强烈地将 GABA 释放到其他抑制性中间神经元上，将乙酰胆碱稀疏地释放到第 1 层中间神经元和其他 VIP+/ChAT+ 中间神经元上。这种基于突触后靶神经元的 ACh 和 GABA 的差异传递反映在 VIP+/ChAT+ 突触前神经元中间末端，因为定量分子分析表明，其中只有一部分专门用于释放乙酰胆碱。此外，我们确定了一个单独的，