Study maps neural projections of Myzus persicae antennae.

The central projections of the sensory neurons of the antennae of Myzus persicae They reach multiple regions of the central nervous system. The mapping included the antennal lobe, antennal mechanosensory and motor centers, subesophageal ganglion, and thoracic neuromeres. The study used mass staining, immunohistochemistry, confocal microscopy, and three-dimensional reconstruction. The results broaden the understanding of the anatomical organization of the aphid's olfactory system.

Myzus persicae It causes economic losses in agriculture. The insect uses olfactory signals to locate hosts and escape predators. Understanding the neural architecture linked to olfaction contributes to interpreting how the insect processes chemical stimuli.

Researchers dissected 30 adult individuals. Six central nervous systems allowed for complete dissection. Four samples received efficient labeling with the Micro-Ruby neural tracer. The team combined the tracer with anti-synapsin antibody to delineate neuropil. Images were obtained using a confocal microscope. The group generated a three-dimensional atlas with the aid of Amira software.

Main projections

The antennal nerve fibers projected primarily to the ipsilateral antennal lobe and to the antennal mechanosensory and motor center. Projections also reached the subesophageal ganglion and the prothoracic, mesothoracic, and metathoracic neuromeres. Two parallel bundles ran along the ventral nerve cord. One bundle innervated three thoracic neuromeres. The other concentrated fibers in the prothoracic neuromere, where it formed a defined neuropillar structure.

In the antennal lobe, the axons outlined glomeruli. Synapsin staining did not show clear glomerular boundaries. The neural tracer allowed visualization of more defined contours. The pattern coincides with previous records in Acyrthosiphon pisum.

Secondary projections

The study identified secondary projections. One fiber originated from the antennal lobe and reached the protocerebral region. Another fiber connected the ipsilateral antennal lobe to the contralateral one. The authors also recorded a projection from the antennal lobe to the calyx. This region is involved in olfactory memory processes in insects. The team also observed two somas in the subesophageal ganglion.

The fibers posterior to the antennal lobe reached the antennal mechanosensory and motor center, an area associated with the control of antennal movements. Some fibers descended to the subesophageal ganglion, the gustatory center. The antennal nerve also projected to motor areas of the thoracic ganglia. The pattern indicates integration between sensory stimuli and motor responses.

The authors suggest using serial transmission electron microscopy to detail synaptic connections. The technique can reveal the fine organization of neural circuits. The three-dimensional map provides an anatomical basis for functional studies on olfactory processing in aphids.

Further information at doi.org/10.3390/insects17030249