Journal club: neuroscience entomology

Feeding-induced rearrangement of green leaf volatiles reduces moth oviposition

The author's painted a very intriguing dynamic of green leaf volatiles (GLV). Typically, from my sample size of 2 other GLV papers from journal club, I think of GLV as chemicals released by the plant in response to damage in order to recruit predators of the organism causing damage.

This paper takes a slight twist in that the GLV is constitutively released by the plant, and it is the caterpillar that changes the isometry of the GLV which in turn attracts the caterpillar's predator! Moreover, the new isomer is also detected by the moth (caterpillar's next life stage) to oviposit (lay eggs) on a different plant as it is more likely that the new isomer indicates predators that could eat the moth's eggs.

Unfortunately, I'm not sure the authors found enough supporting evidence. While they found that the antennal lobe seems to be able to differentiate different isomers, they didn't convincingly show that it was consequential, changes in ovipositon due to different isomer ratios.

With respect to the calcium responses in the antennal lobes, the authors mention that they cannot directly compare individuals due to not having a physiological map of the antennal lobe. Given that, I couldn't work out how they determined the regions of interest (ROIs). If they couldn't define regions before they saw the calcium fluorescent fluxes based on some physiological, did they do it based on the flourescent time course after treatment? Region 3 and 4 seem pretty close, and it seems it could significantly change results if they misplace their region of detection.