Department of Cognitive, Linguistics and Psychological Sciences, Brown University, Providence, RI 02912, USA.
Neuron. 2012 Dec 6;76(5):976-88. doi: 10.1016/j.neuron.2012.10.039.
Postrhinal cortex, rodent homolog of the primate parahippocampal cortex, processes spatial and contextual information. Our hypothesis of postrhinal function is that it serves to encode context, in part, by forming representations that link objects to places. To test this hypothesis, we recorded postrhinal neurons and local field potentials (LFPs) in rats trained on a two-choice, visual discrimination task. As predicted, many postrhinal neurons signaled object-location conjunctions. Another large proportion encoded egocentric motor responses. In addition, postrhinal LFPs exhibited strong oscillatory rhythms in the theta band, and many postrhinal neurons were phase locked to theta. Although correlated with running speed, theta power was lower than predicted by speed alone immediately before and after choice. However, theta power was significantly increased following incorrect decisions, suggesting a role in signaling error. These findings provide evidence that postrhinal cortex encodes representations that link objects to places and suggest postrhinal theta modulation extends to cognitive as well as spatial functions.
后眶回皮层，是灵长类动物旁海马回皮层的啮齿动物同源物，处理空间和上下文信息。我们对后眶回功能的假设是，它通过形成将物体与位置联系起来的表示来编码上下文，部分地编码上下文。为了检验这一假设，我们在接受过两项视觉辨别任务训练的大鼠身上记录了后眶回神经元和局部场电位（LFPs）。正如预测的那样，许多后眶回神经元发出了物体-位置的结合信号。很大一部分神经元编码了以自我为中心的运动反应。此外，后眶回 LFPs 在 theta 波段表现出强烈的振荡节律，许多后眶回神经元与 theta 相位锁定。尽管与跑步速度相关，但 theta 功率在选择前后都低于仅由速度预测的水平。然而，theta 功率在错误决策后显著增加，这表明它在错误信号中起作用。这些发现提供了证据表明后眶回皮层编码了将物体与位置联系起来的表示，并表明后眶回的 theta 调制扩展到认知和空间功能。
