Kesner Raymond P, Gilbert Paul E
Department of Psychology, University of Utah, 380 South 1530 East, Room 502, Salt Lake City, UT 84112, USA.
Eur J Neurosci. 2006 Apr;23(7):1888-94. doi: 10.1111/j.1460-9568.2006.04709.x.
A delayed-match-to-sample task was used to assess memory for motor responses in rats with control, hippocampus, or medial caudate nucleus (MCN) lesions. All testing was conducted on a cheeseboard maze in complete darkness using an infrared camera. A start box was positioned in the centre of the maze facing a randomly determined direction on each trial. On the sample phase, a phosphorescent object was randomly positioned to cover a baited food well in one of five equally spaced positions around the circumference of the maze forming a 180-degree arc 60 cm from the box. The rat had to displace the object to receive food and return to the start box. The box was then rotated to face a different direction. An identical baited phosphorescent object was placed in the same position relative to the start box. A second identical object was positioned to cover a different unbaited well. On the choice phase, the rat must remember the motor response made on the sample phase and make the same motor response on the choice phase to receive a reward. Hippocampus lesioned and control rats improved as a function of increased angle separation used to separate the correct object from the foil (45, 90, 135, and 180 degrees) and matched the performance of controls. However, rats with MCN lesions were impaired across all separations. Results suggest that the MCN, but not the hippocampus, supports working memory and/or a process aimed at reducing interference for motor response selection based on vector angle information.
采用延迟匹配样本任务来评估对照组、海马体或内侧尾状核（MCN）损伤大鼠的运动反应记忆。所有测试均在完全黑暗的棋盘迷宫中使用红外摄像机进行。起始箱位于迷宫中心，每次试验时面向随机确定的方向。在样本阶段，一个磷光物体被随机放置在迷宫圆周上五个等距位置之一，覆盖一个装有诱饵的食物槽，形成一个距起始箱60厘米的180度弧。大鼠必须移动物体以获取食物，然后返回起始箱。然后将起始箱旋转至面向不同方向。一个相同的装有诱饵的磷光物体被放置在相对于起始箱的相同位置。另一个相同的物体被放置在覆盖另一个未装诱饵的食物槽的位置。在选择阶段，大鼠必须记住在样本阶段做出的运动反应，并在选择阶段做出相同的运动反应以获得奖励。海马体损伤大鼠和对照组大鼠随着用于将正确物体与干扰物分开的角度间隔增加（45度、90度、135度和180度）而表现改善，并与对照组的表现相当。然而，MCN损伤的大鼠在所有间隔下均表现受损。结果表明，MCN而非海马体支持工作记忆和/或一个旨在基于向量角度信息减少运动反应选择干扰的过程。
