Structural plasticity of olfactory neuropils in relation to insect diapause

Samples that were physically damaged during technical processing were excluded from analysis, as were those that did not render high quality images during confocal scanning, or had physical abnormalities such as divergent number of calycal cups. In cases where only one of a paired neuropil was discarded for the previously stated reasons, the intact neuropil volume was duplicated as to achieve total neuropil volumes comparable to fully intact samples. As paired neuropils are known to be symmetrical between hemispheres (Galizia et al. 1998; el Jundi et al. 2009; Eriksson et al. 2019) both neuropils were discarded in cases where the volume difference was greater than 10% within a pair. The latter phenomenon is to be expected in cases where the neurolemma was ruptured before samples were fully fixated, allowing damaged tissues to expand post mortem.