Vision of conspecifics decreases the effectiveness of ethanol on zebrafish behaviour

Abstract

Aquatic organisms in pharmacology and toxicology research are often exposed to compounds in isolation prior to physiological or behavioural testing. Recent evidence suggests that the presence of conspecifics during a stressful event can modulate behavioural outcomes (called ‘social buffering’) when testing occurs within the same context. It is unknown, however, whether the social environment during exposure interacts with the efficacy of anxiety-altering substances when subsequently tested in the absence of conspecifics. In this study, zebrafish were individually exposed to habitat water or ethanol (1.0% vol/vol) while untreated conspecifics were visually present or absent during dosing. Using the novel object approach test, a validated test of boldness and anxiety-like behaviour, we observed significantly greater effects of ethanol in isolated fish, compared to fish with a view of conspecifics during dosing. These results were not explained by altered locomotion during exposure, which might otherwise increase drug uptake. This highlights the need to consider the social environment during exposure when conducting and interpreting behavioural research involving drug or toxicant exposure.

Effects of super-class cannabis terpenes beta-caryophyllene and alpha-pinene on zebrafish behavioural biomarkers

“…The treatment vessel (i.e. dosing beaker) was surrounded by white corrugated plastic to reduce any behavioural alterations due to visual conspecific cues 29 . Individual zebrafish randomly assigned to either a control group or to one of the terpene conditions remained in the solution for 10 min.…”

Robust behavioural effects in response to acute, but not repeated, terpene administration in Zebrafish (Danio rerio)

“…Zebrafish remained in the dosing beaker for a period of 10 min. In order to prevent external visual stimulation, a piece of white plastic was placed around the beaker 40 . After the 10-min dosing period, fish were immediately netted and placed into the arena for behavioural testing.…”

The dose makes the poison: Non-linear behavioural response to CO2-induced aquatic acidification in zebrafish (Danio rerio)

“…2a). This test has been validated for zebrafish with drugs known to increase boldness in mammals, like ethanol (Hamilton et al, 2017;Dean et al, 2021) and nicotine (Dean et al, 2020).…”