Neurons without dendrites? – A novel type of neurosecretory cell in locusts

•Small-diameter nerves accompany the lateral nerves of abdominal ganglia in locusts.•These small nerves originate from a pair of putative neurosecretory cells.•These cells do not form any dendritic ramifications within the ganglia.

Small-diameter nerves were found that are associated with the lateral peripheral nerves of the unfused abdominal ganglia of locusts. Such small nerves were observed in about 30% of all cases in Locusta migratoria, more than 60% in Schistocerca gregaria. Retrograde staining of these small nerves showed two somata in the posterior, lateral, and ventral region of an abdominal ganglion. These cells give rise to the small nerves that accompany the big lateral nerves and, on their surface, form putative neurohaemal release sites. Astonishingly the cells do not form any dendritic ramifications within the neuropile of the ganglia.

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