Localization of [3H]-2-deoxy glucose in single molluscan neurones

Abstract

The glucose analog 2-deoxyglucose (2-DG) can be used quantitatively to measure metabolic activity and is widely used qualitatively for mapping functional activity in the brain. The resolution (meaning the full width at half maximum of the grain density distribution around a line source) of the technique using [14C]-2-DG and X-ray film is limited to about 100 .mu.m. Attempts have been made to improve the resolution using [3H]-2-DG and cellular resolution has been achieved in the goldfish retina and with cultured mouse neurons. An anatomical technique for mapping the metabolic activity of individual neurons would be useful for studying invertebrate CNS, which are relatively simple and stereotyped compared to vertebrate brains. The [3H]-2-DG technique was applied to an invertebrate in a study of the Drosophila visual system, although without cellular resolution. Modifications of the [3H]-2-DG technique to demonstrate localization of 2-DG in single neurons of Limax maximus, a gastropod mollusk, with a resolution of less than 1 .mu.m, are presented.