Fadda F, Cocco S, Stancampiano R, Rossetti Z L
Department of Biochemistry and Human Physiology, University of Cagliari, Italy.
Behav Brain Res. 1999 Aug;103(1):71-6. doi: 10.1016/s0166-4328(99)00025-x.
Long-term ethanol consumption in humans and laboratory animals is associated with morphological and functional alterations of brain structures involved in cognitive processes. In the present experiments, we assessed whether voluntary long-term consumption of ethanol by alcohol-preferring (sP) rats under free choice condition with water (also) caused alterations in memory performance and hippocampal acetylcholine (ACh) release in vivo. A group of sP rats were offered a 10% v/v ethanol solution in a free choice with water for 36 weeks; controls had only tap water available. After withdrawal of ethanol, rats were tested in one trial passive avoidance test and thereafter were trained in a food-reinforced radial arm maze task for 12 days. One day after the last session in the radial-arm maze, rats were implanted with a microdialysis probe in the dorsal hippocampus and dialysate concentrations of ACh were measured. No significant differences were observed between sP drinking and control rats in retention latencies in the passive avoidance test, in radial arm-maze performance or in basal levels of hippocampal ACh release. These results show that long-term ethanol consumption by sP rats is not associated with cognitive impairments or with alterations in the hippocampal cholinergic function. To the extent that chronic ethanol intoxication can be considered a causal factor in the development of memory and neurochemical alterations, these results suggest that sP rats self-regulate ethanol consumption so as to avoid intoxication. These findings may challenge the notion that sP rat lines can be considered a valid model of human alcoholism.
人类和实验动物长期摄入乙醇与认知过程中涉及的脑结构的形态和功能改变有关。在本实验中，我们评估了在自由选择条件下，嗜酒（sP）大鼠自愿长期摄入乙醇（同时有水可供选择）是否会导致体内记忆表现和海马乙酰胆碱（ACh）释放的改变。一组sP大鼠在自由选择的情况下可饮用10%（v/v）乙醇溶液和水，持续36周；对照组只提供自来水。乙醇撤药后，对大鼠进行单次被动回避试验测试，然后在食物强化的放射状臂迷宫任务中训练12天。在放射状臂迷宫最后一次训练后的一天，将微透析探针植入大鼠背侧海马，测量透析液中ACh的浓度。在被动回避试验的保留潜伏期、放射状臂迷宫表现或海马ACh释放的基础水平方面，sP饮酒大鼠和对照大鼠之间未观察到显著差异。这些结果表明，sP大鼠长期摄入乙醇与认知障碍或海马胆碱能功能改变无关。就慢性乙醇中毒可被视为记忆和神经化学改变发展的一个因果因素而言，这些结果表明sP大鼠会自我调节乙醇摄入量以避免中毒。这些发现可能会挑战sP大鼠品系可被视为人类酒精中毒有效模型的观点。
