Laboratory of Behavioral Neurobiology, The Rockefeller University, New York, NY, USA.
Laboratory of Behavioral Neurobiology, The Rockefeller University, New York, NY, USA.
Prog Neuropsychopharmacol Biol Psychiatry. 2020 Jan 10;96:109728. doi: 10.1016/j.pnpbp.2019.109728. Epub 2019 Aug 5.
There are numerous clinical and pre-clinical studies showing that exposure of the embryo to ethanol markedly affects neuronal development and stimulates alcohol drinking and related behaviors. In rodents and zebrafish, our studies show that embryonic exposure to low-dose ethanol, in addition to increasing voluntary ethanol intake during adolescence, increases the density of hypothalamic hypocretin (hcrt) neurons, a neuropeptide known to regulate reward-related behaviors. The question addressed here in zebrafish is whether maternal ethanol intake before conception also affects neuronal and behavioral development, phenomena suggested by clinical reports but seldom investigated. To determine if preconception maternal ethanol consumption also affects these hcrt neurons and behavior in the offspring, we first standardized a method of measuring voluntary ethanol consumption in AB strain adult and larval zebrafish given gelatin meals containing 10% or 0.1% ethanol, respectively. We found the number of bites of gelatin to be an accurate measure of intake in adults and a strong predictor of blood ethanol levels, and also to be a reliable indicator of intake in larval zebrafish. We then used this feeding paradigm and live imaging to examine the effects of preconception maternal intake of 10% ethanol-gelatin compared to plain-gelatin for 14 days on neuronal development in the offspring. Whereas ethanol consumption by adult female HuC:GFP transgenic zebrafish had no impact on the number of differentiated HuC neurons at 28 h post-fertilization (hpf), preconception ethanol consumption by adult female hcrt:EGFP zebrafish significantly increased the number of hcrt neurons in the offspring, an effect observed at 28 hpf and confirmed at 6 and 12 days post-fertilization (dpf). This increase in hcrt neurons was primarily present on the left side of the brain, indicating asymmetry in ethanol's actions, and it was accompanied by behavioral changes in the offspring, including a significant increase in novelty-induced locomotor activity but not thigmotaxis measured at 6 dpf and also in voluntary consumption of 0.1% ethanol-gelatin at 12 dpf. Notably, these measures of ethanol intake and locomotor activity stimulated by preconception ethanol were strongly, positively correlated with the number of hcrt neurons. These findings demonstrate that preconception maternal ethanol consumption affects the brain and behavior of the offspring, producing effects similar to those caused by embryonic ethanol exposure, and they provide further evidence that the ethanol-induced increase in hcrt neurogenesis contributes to the behavioral disturbances caused by ethanol.
有许多临床和临床前研究表明，胚胎暴露于乙醇中会显著影响神经元发育，并刺激酒精摄入和相关行为。在啮齿动物和斑马鱼中，我们的研究表明，胚胎暴露于低剂量乙醇除了增加青春期时的自愿性乙醇摄入外，还会增加下丘脑食欲素（hcrt）神经元的密度，食欲素是一种已知调节与奖励相关行为的神经肽。这里在斑马鱼中探讨的问题是，受孕前母亲的乙醇摄入是否也会影响后代的神经元和行为发育，这是临床报告中提出但很少被研究的现象。为了确定受孕前母亲的乙醇消耗是否也会影响这些 hcrt 神经元和后代的行为，我们首先标准化了一种测量 AB 品系成年和幼鱼斑马鱼自愿摄入乙醇的方法，给予分别含有 10%或 0.1%乙醇的明胶餐。我们发现明胶的摄入量与成鱼的摄食量一致，并且是血乙醇水平的有力预测指标，并且也是幼鱼摄食量的可靠指标。然后，我们使用这种喂养模式和活体成像来研究与对照相比，受孕前母亲摄入 14 天 10%乙醇-明胶对后代神经元发育的影响。尽管成年雌性 HuC:GFP 转基因斑马鱼的乙醇消耗对受精后 28 小时（hpf）分化的 HuC 神经元数量没有影响，但受孕前成年雌性 hcrt:EGFP 斑马鱼的乙醇消耗显著增加了后代中 hcrt 神经元的数量，这种影响在 28 hpf 时观察到，并在受精后 6 和 12 天（dpf）时得到证实。这种 hcrt 神经元的增加主要出现在大脑的左侧，表明乙醇作用的不对称性，并且伴随着后代行为的变化，包括在 6 dpf 时对新奇诱导的运动活动显著增加，但在 12 dpf 时对 0.1%乙醇-明胶的自愿消耗没有增加，以及在 12 dpf 时对新奇诱导的运动活动显著增加。值得注意的是，这些受孕前乙醇刺激的乙醇摄入和运动活动的测量与 hcrt 神经元的数量呈强烈的正相关。这些发现表明，受孕前母亲的乙醇消耗会影响后代的大脑和行为，产生类似于胚胎乙醇暴露引起的影响，并提供进一步的证据表明，乙醇诱导的 hcrt 神经发生增加导致了乙醇引起的行为障碍。
