Differential sensitivity of neurosecretory and non‐neurosecretory neurones of an aphid to sucrose during fixation for electron microscopy

Abstract

SUMMARYThe Group 1 neurosecretory cells and a proportion of the non‐neurosecretory cells in the protocerebrum of the aphid Megoura viciae show gross differences in preservation when sucrose is used to increase the osmolarity of a glutaraldehyde primary fixative and an osmium tetroxide secondary fixative. The neurosecretory cells are well preserved whilst a proportion of the non‐neurosecretory cells are shrunken and electron dense, the proportion of affected cells increases with the concentration of sucrose used. This difference is not seen when either the primary or the secondary fixatives are used alone, when a mixture of the primary and secondary fixatives is used or when the osmotic pressure is increased with inorganic salts.