Discussion

There seems to be a negative correlation between action potential frequency and concentration of
imidacloprid. This observation would go along with our initial predictions regarding an existing
negative correlation between both variables.
    Additionally, this negative correlation agrees with the documented effects of clothianidin (a
neonicotinoid similar to imidacloprid): crayfish showed reduced responsiveness to stimulus with
increasing clothianidin concentration (Miles et al, 2017). Thus, by having a similar neonicotinoid
producing similar effects on the action potentials of crayfish neurons, the results obtained in this
experiment may help make clearer what general effects neonicotinoids have on crayfish, and, to
some extent, aquatic invertebrate animals. Lastly, the exhibited reduced responsiveness may be
explained by the mode of action that imidacloprid has, which involves causing a blockage in the
nicotinergic neuronal pathway that leads to the accumulation of acetylcholine, resulting in
paralysis, and eventually, in some cases, death.
    For future research, performing this experiment with treatments at higher concentrations may
determine the point at which action potential propagation ceases altogether. Additionally,
considering that imidacloprid as a pesticide is implicated in the rise of colony collapse disorder
among honeybees, it would be worth to consider how the methods of this study could be
transferred and modified to investigate imidacloprid’s effects on the firing rates of honey bee
neurons.