Effects of Low- and High-LET Radiation on the Salt Chemotaxis Learning in Caenorhabditis elegans

Abstract

High linear energy transfer (LET) radiation is important components of cosmic rays that has neurobiological effects: it is known to induce conditioned taste aversion, and suppress neurogenesis that may underlie cognitive impairment. However, the impact of high-LET radiation on other learning effects remains largely unknown. Here, we focus on kinetics of the radiation response for the salt chemotaxis learning (SCL) behavior in the nameatode, Caenorhabditis elegans, because the SCL during the learning conditioning was modulated after low-LET γ-irradiation. Firstly, the SCL ability was examined following high-LET irradiation (12C, 18.3 MeV/u, LET = 113 keV/μm), revealing its dose-dependent decrease after high- and low-LET exposure. Next, we demonstrate that the SCL at the early phase of the learning conditioning is greatly affected by high- and low-LET irradiation, and interestingly, the magnitude of these effects by high-LET radiation was significantly smaller than that by low-LET one. Moreover, the analysis of gpc-1 mutant showed that the G-protein γ subunit, GPC-1 is responsible for such early phase response. This study is the first to provide the evidence for the kinetics of changes in SCL after high-LET irradiation of C. elegans.