We present method that detects changes in mortality as a consequence of application of a chemical/pharmacological agent. Often is the evaluation of consequential mortality impaired by natural mortality, especially in organisms with high turn of generations, like honeybees. Investigators in the field of olfactory neurophysiology are faced with similar situation in which olfactory receptor neuron is spontaneously active. This activity makes it difficult to evaluate the onset or the offset of the response to a stimulus. The investigators have bridged this issue by developing the detection of response via change of slope in cumulative firing rate of the olfactory receptor neuron. We have adjusted this method to the requirements of toxicological test and used in the analysis lithium toxicity. The method has several steps in which the absolute mortality counts are converted in cumulative sum of dead bees, followed with a normalization of cumulative sum to the last sampling point before the application of the lithium. The changes of the normalized curve from time point to time point are calculated as slope, which is then statistically compared between groups. The method was validated on unrelated dataset, giving an estimation of the duration of agents' effect.• Contain between 1 and 3 bullet points highlighting the customization rather than the steps of the procedure.○ The method enables to evaluate the toxicological effect of the tested substance by overcoming the issues related to natural mortality and difference between tested biological systems, here specifically demonstrating its utility and effectiveness in evaluating the impact of lithium on honeybee colonies mortality rate.○ Simple set up of conditions for toxicological testing in honeybee colonies is described.○ Shorten the window to exclude the history since there is no refractory period is known within normal mortality rate.
Keywords: Cumulative; Firing rate; Slope change; Toxicology.
© 2020 The Author. Published by Elsevier B.V.