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.