Emergence of consistent intra-individual locomotor patterns during zebrafish development

Abstract

The analysis of larval zebrafish locomotor behavior has emerged as a powerful indicator of perturbations in the nervous system and is used in many fields of research, including neuroscience, toxicology and drug discovery. The behavior of larval zebrafish however, is highly variable, resulting in the use of large numbers of animals and the inability to detect small effects. In this study, we analyzed whether individual locomotor behavior is stable over development and whether behavioral parameters correlate with physiological and morphological features, with the aim of better understanding the variability and predictability of larval locomotor behavior. Our results reveal that locomotor activity of an individual larva remains consistent throughout a given day and is predictable throughout larval development, especially during dark phases, under which larvae demonstrate light-searching behaviors and increased activity. The larvae’s response to startle-stimuli was found to be unpredictable, with no correlation found between response strength and locomotor activity. Furthermore, locomotor activity was not associated with physiological or morphological features of a larva (resting heart rate, body length, size of the swim bladder). Overall, our findings highlight the areas of intra-individual consistency, which could be used to improve the sensitivity of assays using zebrafish locomotor activity as an endpoint.

Morphine alleviates pain after heart cryoinjury in zebrafish without impeding regeneration

“…Nonetheless, when the test groups are compared individually, the lidocaine-treated fish swim at 6H significantly slower than at 2H (Figure S1A), consistent with its sedative effect. In agreement with the studies showing high variability in locomotor behavior both in larvae (Fitzgerald et al, 2019) and in adults (Lange et al, 2013), we also noticed a high variability in the swimming speed between the individual fish across all groups, highlighting the complexity of behavioral studies.…”

Hypo- or hyperactivity of zebrafish embryos provoked by neuroactive substances: a review on how experimental parameters impact the predictability of behavior changes

“…Both authors concluded that activity was less variable when measured in the afternoon. In contrast to both studies, Fitzgerald et al [37] reported that time of day did not change the activity of 5, 6 and 7 dpf larvae in the dark period of LMR-L/D measured at 9 a.m and 2 p.m., and activity was more variable in the afternoon rather than in the morning. However, a different temperature (26 °C versus 28 °C of the other studies) was used as rearing temperature and the controversial finding may have been caused by differences in growth and developmental stage.…”

A systems biology approach reveals neuronal and muscle developmental defects after chronic exposure to ionising radiation in zebrafish

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