Graduate School of Medicine, Yamaguchi University, Ube-shi, Yamaguchi-ken, Japan.
PLoS One. 2013 Jul 31;8(7):e70756. doi: 10.1371/journal.pone.0070756. Print 2013.
Hippocampal function is important in the acquisition of negative patterning but not of simple discrimination. This study examined rat hippocampal theta activity during the acquisition stages (early, middle, and late) of the negative patterning task (A+, B+, AB-). The results showed that hippocampal theta activity began to decline transiently (for 500 ms after non-reinforced stimulus presentation) during the late stage of learning in the negative patterning task. In addition, this transient decline in hippocampal theta activity in the late stage was lower in the negative patterning task than in the simple discrimination task. This transient decline during the late stage of task acquisition may be related to a learning process distinctive of the negative patterning task but not the simple discrimination task. We propose that the transient decline of hippocampal theta activity reflects inhibitory learning and/or response inhibition after the presentation of a compound stimulus specific to the negative patterning task.
海马功能在负模式形成的获取中很重要，但在简单辨别中不重要。本研究在负模式形成任务（A+、B+、AB-）的获取阶段（早期、中期和晚期）检查了大鼠海马体θ活动。结果表明，在负模式形成任务的学习晚期，海马体θ活动开始短暂下降（在无强化刺激呈现后 500 毫秒内）。此外，在负模式形成任务中，这种在晚期的海马体θ活动的短暂下降低于简单辨别任务。在任务获取的晚期发生的这种短暂下降可能与负模式形成任务特有的学习过程有关，但与简单辨别任务无关。我们提出，海马体θ活动的短暂下降反映了在呈现特定于负模式形成任务的复合刺激后抑制性学习和/或反应抑制。
