Organization of the parallel antennal-lobe tracts in the moth

The olfactory pathways of the insect brain have been studied comprehensively for more than 40 years, yet the last decade has included a particularly large accumulation of new information relating to this system's structure. In moths, sharp intracellular recording and staining has been used to elucidate the anatomy and physiology of output neurons from the primary olfactory center, the antennal lobe. This review concentrates on the connection patterns characterizing these projection neurons, which follow six separate antennal-lobe tracts. In addition to highlighting the connections between functionally distinct glomerular clusters and higher-order olfactory neuropils, we discuss how parallel tracts in the male convey distinct features of the social signals released by conspecific and heterospecific females. Finally, we consider the current state of knowledge regarding olfactory processing in the moth's protocerebrum and make suggestions as to how the information concerning antennal-lobe output may be used to design future studies.

Automated summary

This paper reviews new information on the structure of the insect olfactory pathways, with a focus on the connection patterns of output neurons from the antennal lobe in moths. The study reveals that the antennal lobe transmits information through six separate tracts and identifies how male moths transmit distinct signals from conspecific and heterospecific females through parallel tracts.