Coiling is a well-preserved behaviour of zebrafish embryos. Since it follows a certain pattern, it can be used to detect changes caused by stressors.
The developing nervous system of a zebrafish embryo lays the foundation for sensing and responding to stimuli that are essential for survival. The first sign of successful neurulation is a repeated twitching of the tail in the chorion, starting even before 24 hours have passed.
This observable coiling provides a sensitive method for detecting the effects of environmental stressors, even at low concentrations. Currently, we use the coiling assay to investigate possible effects of different antidepressants, including venlafaxine.