Data from: A serial multiplex immunogold labeling method for identifying peptidergic neurons in connectomes

Electron microscopy-based connectomics aims to comprehensively map synaptic connections in neural tissue. However, current approaches are limited in their capacity to directly assign molecular identities to neurons. Here, we use serial multiplex immunogold labeling (siGOLD) and serial-section transmission electron microscopy (ssTEM) to identify multiple peptidergic neurons in a connectome. The high immunogenicity of neuropeptides and their broad distribution along axons, allowed us to identify distinct neurons by immunolabeling small subsets of sections within larger series. We demonstrate the scalability of siGOLD by using 11 neuropeptide antibodies on a full-body larval ssTEM dataset of the annelid Platynereis. We also reconstruct a peptidergic circuitry comprising the sensory nuchal organs, found by siGOLD to express pigment-dispersing factor, a circadian neuropeptide. Our approach enables the direct overlaying of chemical neuromodulatory maps onto synaptic connectomic maps in the study of nervous systems.

基于电子显微镜的连接组学（connectomics）旨在全面绘制神经组织内的突触连接图谱。然而，当前方法在直接为神经元赋予分子身份标识的能力上存在局限。本研究中，我们利用连续多重免疫金标记（serial multiplex immunogold labeling, siGOLD）与连续切片透射电子显微镜（serial-section transmission electron microscopy, ssTEM），在连接组中鉴定出多种肽能神经元。神经肽具有较高的免疫原性，且沿轴突广泛分布，这使得我们能够通过对完整大切片系列中的少量子切片进行免疫标记，来区分不同的神经元。我们通过在环节动物Platynereis的幼虫全身ssTEM数据集上使用11种神经肽抗体，验证了siGOLD的可扩展性。此外，我们还重构了包含感觉颈器的肽能神经环路——经siGOLD检测，该环路表达色素分散因子（pigment-dispersing factor），一种昼夜节律相关神经肽。本研究方法可实现在神经系统研究中，将化学神经调节图谱直接叠加至突触连接组图谱之上。