Departamento de Ciencias Farmacéuticas y de la Alimentación. Facultad de Farmacia. Universidad CEU-San Pablo, Madrid, Spain.
Neurobiol Learn Mem. 2011 May;95(4):491-7. doi: 10.1016/j.nlm.2011.02.012. Epub 2011 Mar 1.
Lewis and Fischer-344 rats have been proposed as an addiction model because of their differences in addiction behaviour. It has been suggested that drug addiction is related to learning and memory processes and depends on individual genetic background. We have evaluated learning performance using the eight-arm radial maze (RAM) in Lewis and Fischer-344 adult rats undergoing a chronic treatment with cocaine. In order to study whether morphological alterations were involved in the possible changes in learning after chronic cocaine treatment, we counted the spine density in hippocampal CA1 neurons from animals after the RAM protocol. Our results showed that Fischer-344 rats significantly took more time to carry out test acquisition and made a greater number of errors than Lewis animals. Nevertheless, cocaine treatment did not induce changes in learning and memory processes in both strains of rats. These facts indicate that there are genetic differences in spatial learning and memory that are not modified by the chronic treatment with cocaine. Moreover, hippocampal spine density is cocaine-modulated in both strains of rats. In conclusion, cocaine induces similar changes in hippocampal neurons morphology that are not related to genetic differences in spatial learning in the RAM protocol used here.
Lewis 和 Fischer-344 大鼠由于其成瘾行为的差异而被提议作为成瘾模型。有人认为，药物成瘾与学习和记忆过程有关，并且取决于个体的遗传背景。我们使用八臂放射迷宫 (RAM) 评估了 Lewis 和 Fischer-344 成年大鼠在慢性可卡因治疗下的学习表现。为了研究慢性可卡因治疗后学习可能发生的变化是否涉及形态改变，我们在 RAM 方案后计算了海马 CA1 神经元的棘突密度。我们的结果表明，Fischer-344 大鼠在进行测试获取时明显花费更多的时间并且比 Lewis 动物犯更多的错误。然而，可卡因治疗并没有在两种大鼠品系中引起学习和记忆过程的变化。这些事实表明，在空间学习和记忆方面存在遗传差异，而这些差异不受慢性可卡因治疗的影响。此外，海马棘突密度在两种大鼠品系中都受到可卡因的调节。总之，可卡因在海马神经元形态上引起相似的变化，而与这里使用的 RAM 方案中空间学习的遗传差异无关。
