Role of striatal GABAergic neuron system in learning behavior

纹状体被认为不仅涉及感觉或运动控制，还涉及记忆和学习等认知功能。我们研究了纹状体红藻氨酸损伤对各种学习行为的影响，纹状体红藻氨酸损伤会诱导纹状体中选择性神经元细胞死亡。患有纹状体损伤的老鼠在空间学习任务中表现出严重的缺陷，尽管它们在辨别学习和经典条件反射方面没有表现出任何缺陷。本研究调查了这些动物学习缺陷的机制以及纹状体神经元，特别是纹状体GABA能神经元在学习和记忆中的作用。每次试验前全身给予GABA_A激动剂可显着改善纹状体红藻氨酸损伤大鼠的Morris水迷宫和径向迷宫任务表现，而GABA_B激动剂则不然。这表明大脑中的 GABA_A 受体与纹状体受损动物的学习缺陷有关。由于纹状体 GABA 神经元投射到三个区域，因此我们使用之前接受过该任务训练的正常大鼠测试了微注射 GABA_A 拮抗剂对径向迷宫行为的影响。结果，注射到黑质网状部最明显地增加了错误的数量，注射到纹状体也有显着的影响。综上所述，含有纹状体的神经回路，尤其是纹状体 GABA 能神经元系统，在空间记忆任务的执行中发挥着重要作用。

The striatum has been suggested to be involved not only in the sensory or motor control but also in cognitive function such as memory and learning. We have investigated the effects of striatal kainic acid lesions, which induce selective neuronal cell death in the striatum, on various kinds of learning behavior. Rats with striatal lesions showed severe deficits in spatial learning tasks though they did not show any deficits in discrimination learning and classical conditioning. The present study investigated the mechanism of learning deficits in these animals and the role of striatal neurons, especially striatal GABAergic neurons, in learning and memory.GABA_A agonist systemically administered before each trial significantly improved the performance of Morris water maze and radial maze tasks in rats with striatal kainic acid lesions, while GABA_B agonist did not. This suggests that GABA_A receptors in the brain are involved in the learning deficits of striatal lesioned animals. Since there are three areas to which striatal GABA neurons project, we then tested the effects of microinjection of GABA_A antagonist on radial maze behavior using normal rats previously trained in this task. As a result, injection into the substantia nigra pars reticulata most distinctly increased the number of errors, and injection into the striatum also had significant effects. Taken together it was suggested that a neural circuit containing the striatum, especially the strionigral GABAergic neuron system, plays an important role in performance of spatial memory tasks.