Pinheiro-da-Silva Jaquelinne, Araujo-Silva Heloysa, Luchiari Ana Carolina
Departamento de Fisiologia e Comportamento, Universidade Federal do Rio Grande do Norte, Natal, Brazil.
Int J Dev Neurosci. 2021 Aug;81(5):416-427. doi: 10.1002/jdn.10112. Epub 2021 Apr 20.
Fetal alcohol spectrum disorder (FASD) is the most common cause of birth defects. The severe variations are in fetal alcohol syndrome (FAS) but the most frequent cases are alcohol-related neurodevelopmental disorder (ARND), which is of a difficult diagnosis. ARND characteristics include impaired social behavior, anxiety and depression prevalence, cognitive deficits, and an increased chance for drug addiction. Here, we aimed to test whether early alcohol exposure leads to later alcohol preference. We hypothesize that early alcohol exposure increases the reinforcing effects on later experiences, raising the chance of addiction in adult life. Lately, the zebrafish has been a valuable model on alcohol research, allowing embryonic exposure and the study of the ontogenetic effects. For this, embryos were exposed to three different alcohol treatments: 0.0%, 0.25% and 0.5%, for 2 hr, at 24-hr post-fertilization. Then we evaluated the effects of embryonic alcohol exposure on conditioned place preference in two developmental stage: fry (10 days post-fertilization (dpf)) and young (90 dpf) zebrafish. Results show that control fish presented alcohol associative learning, which means, changes in place preference due to alcohol exposure, at both ontogenetic phases. However, zebrafish exposed to 0.25 and 0.5% alcohol during embryogenesis did not show conditioning response at any evaluated stage. These results suggest perception and cognitive deficits due to embryonic alcohol exposure that can alter alcohol responsiveness throughout a lifetime. Although low alcohol doses do not provoke malformation, it has been shown to induce several neurological and behavioral changes that are termed as Alcohol-Related Neurodevelopmental Disorders. These results may contribute to future investigations on how embryonic exposure affects the neurocircuitry related to perception and associative learning processing.
胎儿酒精谱系障碍（FASD）是出生缺陷的最常见原因。严重的变异表现为胎儿酒精综合征（FAS），但最常见的情况是酒精相关神经发育障碍（ARND），其诊断较为困难。ARND的特征包括社交行为受损、焦虑和抑郁患病率增加、认知缺陷以及药物成瘾几率增加。在此，我们旨在测试早期酒精暴露是否会导致后期对酒精的偏好。我们假设早期酒精暴露会增加对后期经历的强化作用，从而增加成年后成瘾的几率。最近，斑马鱼已成为酒精研究的宝贵模型，可用于胚胎暴露及个体发育影响的研究。为此，在受精后24小时，将胚胎暴露于三种不同的酒精处理中：0.0%、0.25%和0.5%，持续2小时。然后我们在两个发育阶段评估胚胎酒精暴露对条件性位置偏好的影响：幼鱼（受精后10天（dpf））和幼鱼（90 dpf）斑马鱼。结果表明，对照鱼在两个个体发育阶段均表现出酒精联想学习，即由于酒精暴露导致的位置偏好变化。然而，在胚胎发育期间暴露于0.25%和0.5%酒精的斑马鱼在任何评估阶段均未表现出条件反应。这些结果表明，胚胎酒精暴露会导致感知和认知缺陷，从而可能会改变一生的酒精反应性。尽管低剂量酒精不会引发畸形，但已证明它会诱发多种神经和行为变化，这些变化被称为酒精相关神经发育障碍。这些结果可能有助于未来关于胚胎暴露如何影响与感知和联想学习处理相关的神经回路的研究。
