Neuropharmalogical Effects of Acute Terpinolene Administration on Zebrafish Behaviour

Abstract

Anxiety disorders are prevalent worldwide and have worsened with the COVID-19 pandemic. There are numerous treatments for anxiety that range from behavioural therapies to pharmacological ones. Still, there is no gold standard that works for everyone, and therefore a need to examine non-traditional treatments. Previous studies have used animal models to test the effect of terpenes on anxiety-like behaviour in rodents and zebrafish. Acute limonene exposure was found to regulate anxiety-like behaviour in mice and zebrafish. Terpinolene is a similar terpene with therapeutic properties previously established to produce antinociceptive and anti-inflammatory effects from action on the serotonergic pathways in the central nervous system. This study examined whether terpinolene could alter anxiety-like behaviour and locomotion in zebrafish. To answer this question, we measured behaviour relating to general locomotor activity levels, anxiety, and willingness to explore a new environment in an open field test and novel object approach test after exposure to terpinolene at 0.01%, 0.05%, and 0.1% concentrations. Terpinolene had significant effects on anxiety-like measures in the open field test, such as time spent in the thigmotaxis (outer) or center zone, as well as locomotor variables, swimming velocity and immobility at the 0.1% dose. However, when a novel object was introduced to the arena, there were no significant increases in boldness to that object. This study demonstrates that terpinolene can have a sedative or anxiolytic effect in zebrafish and may have potentially valuable medicinal properties.

Faculty Mentor: Dr. Trevor Hamilton