HTR5A and Anxiety: Anotherpathway that is involved in anxiety is the serotonergicpathway, and when the animal presentsan anxiogenic pattern in the light–dark test, it is relatedto the presence of high extracellular levels of 5-HT in the zebrafishbrain, on the other hand, with reducedlevels, they generally cause anxiolytic behaviors. The 5HT1A pathway is associated with antidepressant and/oranxiolytic effects, being an inhibitory receptor coupled to the Gprotein.