Chen L L, Lin L H, Barnes C A, McNaughton B L
Behavioral Neuroscience Program, University of Colorado, Boulder 80309.
Exp Brain Res. 1994;101(1):24-34. doi: 10.1007/BF00243213.
This study investigated the effects of visual and ideothetic cues on the spatial tuning of head-direction (HD) cells recorded in the rat posterior cortices. Extracellular, single unit responses were recorded from animals performing each of two different tasks, a spatial working memory task on a radial-arm maze and a passive rotation task on a modified "lazy Susan" platform. The influence of visual cues was assessed by manipulating the position of one white and three black cue-cards placed around the maze. We found three major categories of HD cells based on their response to cue manipulations in the maze tasks. Type A cells (10/41) rotated their preferred directions along with the rotation of the cues. The majority (type B, 25/41) of the HD cells were unaffected by the rotation of visual cues, maintaining their established preferred direction. Type C cells (6/41) showed complex responses to cue rotation, with the preferred direction reflecting either a combination of both type A and type B responses or an unpredictable response. The results indicate that the internal representation of directionality can be calibrated by visual cues and that some mnemonic processes may have been involved in the registration of the previous cue locations. Eleven cells were tested in both the maze task and the passive rotation task. Most (9/11) showed a significant directionality in the former task, but showed either no or weak directionality in the latter task, suggesting that movement-related ideothetic cues may be used in supporting the directional firing of these cells. Only two cells showed significant directionality in both tasks. Their established preferred directions did not rotate along with the cues in the maze task, but did rotate with the cues in the passive rotation task. We conclude that the dynamic aspect of the directional tuning in these cortical HD cells may represent on-line calibration of an angular coordinate representation.
本研究调查了视觉和本体感受线索对大鼠后皮质中记录的头方向（HD）细胞空间调谐的影响。从执行两种不同任务的动物身上记录细胞外单单位反应，这两种任务分别是在放射状臂迷宫上的空间工作记忆任务和在改良的“懒人转盘”平台上的被动旋转任务。通过操纵放置在迷宫周围的一张白色和三张黑色提示卡的位置来评估视觉线索的影响。基于它们在迷宫任务中对提示操纵的反应，我们发现了HD细胞的三大类。A类细胞（10/41）随着提示的旋转而旋转其偏好方向。大多数HD细胞（B类，25/41）不受视觉提示旋转的影响，保持其既定的偏好方向。C类细胞（6/41）对提示旋转表现出复杂的反应，其偏好方向反映了A类和B类反应的组合或不可预测的反应。结果表明，方向性的内部表征可以通过视觉线索进行校准，并且一些记忆过程可能参与了先前提示位置的记录。在迷宫任务和被动旋转任务中对11个细胞进行了测试。大多数细胞（9/11）在前一个任务中表现出显著的方向性，但在后一个任务中表现出无方向性或弱方向性，这表明与运动相关的本体感受线索可能用于支持这些细胞的定向放电。只有两个细胞在两个任务中都表现出显著的方向性。它们既定的偏好方向在迷宫任务中不随提示旋转，但在被动旋转任务中随提示旋转。我们得出结论，这些皮质HD细胞定向调谐的动态方面可能代表角度坐标表征的在线校准。
