Development of a vibrational startle response assay for screening environmental pollutants and drugs impairing predator avoidance

Abstract

The present paper describes the Vibrational Startle Response Assay (VSRA), a new robust, simple and automated in vivo medium-to high-throughput procedure for assessment of the escape response and its habituation in zebrafish larvae. Such behaviors enable fish larvae to escape from predator strikes in aquatic ecosystems. The assay is based on measuring the distance moved by each larva during the startle response evoked by repetitive vibrational stimuli. The iterative reduction observed in the response to a series of tapping stimulus in VSRA met the main criteria of habituation. Subsequently, the analysis of concordance using a battery of neuroactive compounds modulating different neurotransmitter systems demonstrated that the results of VSRA are highly predictive of the effects on other vertebrates. Finally, as a proof of concept, VSRA was used to test two relevant environmental pollutants at different concentrations. The results demonstrated that VSRA is suitable for concentration-response analysis of environmental pollutants, opening the possibility to determine the potency and the associated hazard of impaired escape response for the different compounds. Therefore, we suggest that VSRA could be a valuable tool for screening of chemical compounds capable of compromising predator avoidance behavior.

Pharmacological Modulation of Serotonin Levels in Zebrafish Larvae: Lessons for Identifying Environmental Neurotoxicants Targeting the Serotonergic System

“…In a similar way, the prototypic SERT inhibitor fluoxetine also decreased 7 dpf zebrafish larvae escape response in the bouncing ball assay following acute exposure [34]. Non-associative learning has been studied in zebrafish larvae by monitoring the reduction in a startle response to a series of acoustic or vibrational stimuli [22,35]. Similar to this study and under the same exposure conditions, in a previous study, both compounds impaired zebrafish larvae by rapid decrease of larvae movement following consecutive tapping stimuli [22].…”

“…A battery of behavioral tests including basal locomotor (BLM) activity, visual motor response (VMR), the acoustic/vibrational escape response (also referred as startle response) and the habituation of the startle response were used to assess the behavioral profile in zebrafish larvae exposed to prototypic compounds inhibiting MAO (deprenyl), SERT (fluoxetine), and TPH (PCPA) activities. The selected concentrations were the same as those used in a previous study [22], and similar to the latter study, no system toxicity or morphological effects were observed in larvae following exposure. A significant effect in larvae BLM was found in those exposed to deprenyl, fluoxetine, and PCPA (Figure 2A) (H(5) = 37.310, p = 0.000).…”

“…Non-associative learning has been studied in zebrafish larvae by monitoring the reduction in a startle response to a series of acoustic or vibrational stimuli [22,35]. Similar to this study and under the same exposure conditions, in a previous study, both compounds impaired zebrafish larvae by rapid decrease of larvae movement following consecutive tapping stimuli [22]. It has been reported that serotonergic neurons in addition to the Mauthner cells play an important role in the regulation of this form of learning in zebrafish; for example, Pantoja et al (2016) reported decrease of total distance moved by larvae under habituation conditions following the treatment with quipazine, a serotonin receptor agonist [36].…”

Evaluation of the Adverse Effects of Chronic Exposure to Donepezil (An Acetylcholinesterase Inhibitor) in Adult Zebrafish by Behavioral and Biochemical Assessments

“…This assay was conducted to evaluate the habitation and escape response in zebrafish larvae. From the results, DPZ was found to be consistent with its acetylcholine receptor agonist role by significantly increasing the magnitude of startle response, area under the curve (AUC) value, and reduced habituation to VSR [14,15]. In another prior study, zebrafish larvae were also used for behavior analysis, with the help of a series of acoustic stimuli.…”

Visual learning and its underlying neural substrate in two species of teleost fish (Zebrafish and Ambon damselfish)

“…One of these key characteristics is a spontaneous recovery after a period of rest when the stimulus is absent (Thompson and Spencer, 1966). Another, referred to as dishabituation, is the recovery of the response after a different stimulus is presented (Rodgers et al, 1963;Rankin et al, 1990;Giles and Rankin, 2009;Faria et al, 2019). Finally, another way to differentiate habituation from other phenomena is by being able to modulate its rate with changes in the features of the stimulus (e.g.…”