Original Research ARTICLE
Individual differences in hatching time predict alcohol response in zebrafish
- 1Federal University of Rio Grande do Norte, Brazil
There are significant individual differences in response to alcohol: some people seem to exhibit higher alcohol sensitivity, while others are more resistant. These differences are related to alcohol metabolism, inherited traits, environmental/social pressure, personal habits and other indeterminate causes. In order to test how individual differences in hatching time are related to behavioral response to different alcohol concentrations, we separated zebrafish larvae into two categories according to egg emergence time: eggs hatched between 48 and 72 hours post-fertilization (hpf) were considered early emerging (EE), while those hatched from 72 to 96hpf were considered late emerging (LE). On the 30th day post fertilization, EE and LE fish were exposed to 4 alcohol concentrations: 0.00% (control), 0.10%, 0.25% and 0.50%, and behavior was recorded for 60 min. We observed average and maximum swimming speed, distance traveled, and freezing time (immobility that indicates state of anxiety). For EE fish, 0.10% alcohol did not change behavior, while 0.25% and 0.50% increased freezing and decreased locomotion. By contrast, LE fish increased locomotion when exposed to both 0.10 and 0.25% alcohol, and increased freezing time at 0.50% alcohol. These results show that zebrafish behavioral profiles exhibit different sensitivities to alcohol, likely due to traits that can be tracked from early life stages and may indicate individuals’ predisposition to alcohol tolerance and dependence.
Keywords: Ethanol, egg emergence, Anxiety, Locomotion, Personality
Received: 19 Mar 2019;
Accepted: 08 Jul 2019.
Edited by:Nazzareno Cannella, School of Pharmaceutical Sciences and Health Products, University of Camerino, Italy
Reviewed by:Matthew O. Parker, University of Portsmouth, United Kingdom
Aleksei Y. Egorov, Institute of Evolutionary Physiology and Biochemistry (RAS), Russia
Fulvio Plescia, Department of Health Promotion, Maternal-Infant, Internal and Specialized Medicine of Excellence G. D'Alessandro, University of Palermo, Italy
Copyright: © 2019 Leite-Ferreira, Araujo-Silva and Luchiari. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Mx. Ana C. Luchiari, Federal University of Rio Grande do Norte, Natal, 84030-900, Rio Grande do Norte, Brazil, email@example.com