The Effect of Hypoxia on the Nervous System of Aplysia californica

The intertidal zone of California’s Pacific coast is home to the marine snail known as Aplysia californica, an organism that has found use as a model in experiments focused on understanding the basis of learning and memory. Its simple nervous system consisting of easily identifiable neurons, its life span of a year, and a readily-accessed aquacultured source from the National Resource for Aplysia make it an excellent model for ontogenetic, neural, and behavioral studies. Here, however, the focus was on strategies this species uses to survive in an environment rife with risks of hypoxia and desiccation during the tidal cycle. Two reflex behaviors, the “time to right” and the “tail withdrawal reflex”, were studied before and after administration of hypoxic exposures designed to simulate those they encounter naturally. It was proposed that there would be no significant difference in behavioral times due to the organism’s adaptations to its environment, specifically its ability to manipulate its metabolic rate. Hypoxia was induced by administering a treatment of reduced O2 content seawater for four hours, or out-of-water treatments of either one hour or six hours, and compared to no-treatment controls. Analysis of the times to execute reflexes confirmed that no significant differences were detected either before and after hypoxia or when compared to controls. These results suggest that Aplysia californica is well-adapted to its changing environment