# Central Projections of Antennal Sensory Neurons in the Aphid Myzus persicae

## TL;DR

This study maps the central projections of antennal neurons in the aphid Myzus persicae, revealing their connections to various brain regions and highlighting the sensory organ's role in behavior.

## Contribution

The first systematic mapping of antennal sensory neuron projections in the central nervous system of Myzus persicae.

## Key findings

- Antennal neurons project to the ipsilateral antennal lobe and mechanosensory center, as well as the ventral nerve cord.
- Some axons reach the contralateral antennal lobe, calyx, and protocerebrum, indicating diverse sensory roles.
- The findings establish the anatomical basis for understanding olfactory processing in aphids.

## Abstract

This study investigated the central projections of antennal neurons in the aphid Myzus persicae. Our results show that these neurons primarily project to the ipsilateral antennal lobe and antennal mechanosensory and motor center, with some fibers projecting to the ventral nerve cord, the calyx, the protocerebrum, the contralateral antennal lobe and the contralateral antennal nerve. The numerous neuropils innervated by antennal neural axons suggest the multiple roles of this sensory organ in aphid behavior. These findings provide information about the anatomical arrangement of the olfactory nervous system in M. persicae and serve as a basis for future research on aphid sensory processing.

The aphid Myzus persicae is an important agricultural pest relying on olfactory cues to find food and escape from predators. The considerable difficulty of anatomical manipulation and other related technical challenges may underlie the absence of studies systematically mapping the central projections of antennal sensory neurons in its central nervous system. We used mass stain, immunohistochemistry, laser scanning confocal microscope and three-dimensional reconstruction techniques to trace the central projections of sensory neurons from the antennae. The ipsilateral antennal nerve targets mainly the antennal lobe, the antennal mechanosensory and motor center, and most neuromeres of the ventral nerve cord. There are also several axons that project to other regions, like the contralateral antennal lobe, the contralateral antennal nerve, the ipsilateral calyx and some region of the protocerebrum. The numerous neuropils innervated by axons from the antenna indicate the multiple roles that this sensory organ serves in insect behavior, and the results which provide information about the basic anatomical arrangement of the olfactory nervous system in aphid M. persicae may provide some basic knowledge for the further investigations of the aphid.