Effects of High-LET Particles (⁴⁰A) on the Brain of Drosophila Melanogaster

Summary

To investigate the effects of galactic heavy particles on nervous tissue, Drosophila melanogaster flies were exposed to ⁴⁰A from the Super-HILAC accelerator at the Lawrence Berkeley Laboratory. The energy of the particles reaching the Drosophila neurons was 4·8 MeV/nucleon, and the fluence ranged from 6 × 10⁴ to 8 × 10⁷ particles/cm². Thirty-five days after irradiation at the higher fluences, extensive tissue fragmentation and cysts were found. At fluences as low as one hit/two cell bodies (about 5 × 10⁶) and one hit/90 cell bodies (about 9 × 10⁴ particles/cm² or 21 rad average dose) swelling of neuronal cytoplasm and focally fragmented membranes were noted; at fluences ranging from one hit/six to one hit/135 cell bodies, there was frequently a marked increase in glial lamellae around nerve-cell processes, which often had degenerative features. These findings support the view that single hits by heavy particles may injure nervous tissue.