Diferenças comportamentais na resposta ao álcool em peixes juvenis de peixe zebrafish (Danio rerio)

Abstract

Alcohol (ethanol or ethyl alcohol) is undoubtedly the most widely used legal drug of abuse in the world. The excessive use of this substance can cause substance use disorder, one of the most devastating diseases among those related to drugs of abuse. The reinforcing effects of moderate alcohol use are the result of the interaction with neurotransmitter systems such as, for example, dopamine (DA), serotonin (5HT), gamma-aminobutyric acid (GABA) and glutamate. However, we know that some individuals are more sensitive to the effects of alcohol while others are more resistant, a response that may be related to genetic and environmental / social factors. Determining the relationship between the behavioral profile and alcohol use is difficult, since both the individual's behavioral and neurophysiological analysis must be taken into account. In order to better understand these aspects of alcohol consumption, the zebrafish (Danio rerio) has become a promising model animal, because it offers the chance to investigate alcohol and individual differences effects, it presents classic vertebrate neurotransmitters, and shows high genetic similarity with humans. Another advantage is the well-known behavioral repertoire derived from zebrafish alcohol exposure, which also shows similarities to human behavior. In this sense, this work evaluated through behavioral tests whether individual differences established early in life can be predictive of the effects of alcohol consumption. The results show that early emergent animals alter their behavior in moderate concentrations of alcohol, such as 0.25% while late emerging animals have their behavior altered in low concentrations of alcohol, such as 0.10%. In addition, early emerging are more prone to risk, explore the environment more and make faster decisions as opposed to late emerging. In this study it was possible to observe that individual differences appear from an early age in an individual's life. Animals with different hatching times differ behaviorally when exposed to alcohol, early emerging are more resistant to alcohol while late emerging are more sensitive, so that early emerging have behavioral characteristics similar to the bold profile, while late emerging are closer to the profile shy.