Yoder Ryan M, Chan Jeremy H M, Taube Jeffrey S
Department of Psychological & Brain Sciences, Dartmouth College.
Behav Neurosci. 2017 Aug;131(4):312-24. doi: 10.1037/bne0000205.
Acetylcholine contributes to accurate performance on some navigational tasks, but details of its contribution to the underlying brain signals are not fully understood. The medial septal area provides widespread cholinergic input to various brain regions, but selective damage to medial septal cholinergic neurons generally has little effect on landmark-based navigation, or the underlying neural representations of location and directional heading in visual environments. In contrast, the loss of medial septal cholinergic neurons disrupts navigation based on path integration, but no studies have tested whether these path integration deficits are associated with disrupted head direction (HD) cell activity. Therefore, we evaluated HD cell responses to visual cue rotations in a familiar arena, and during navigation between familiar and novel arenas, after muscarinic receptor blockade with systemic atropine. Atropine treatment reduced the peak firing rate of HD cells, but failed to significantly affect other HD cell firing properties. Atropine also failed to significantly disrupt the dominant landmark control of the HD signal, even though we used a procedure that challenged this landmark control. In contrast, atropine disrupted HD cell stability during navigation between familiar and novel arenas, where path integration normally maintains a consistent HD cell signal across arenas. These results suggest that acetylcholine contributes to path integration, in part, by facilitating the use of idiothetic cues to maintain a consistent representation of directional heading. (PsycINFO Database Record
乙酰胆碱有助于在一些导航任务中表现准确，但对其对潜在脑信号的贡献细节尚未完全理解。内侧隔区向各个脑区提供广泛的胆碱能输入，但内侧隔胆碱能神经元的选择性损伤通常对基于地标导航或视觉环境中位置和方向的潜在神经表征影响很小。相比之下，内侧隔胆碱能神经元的丧失会破坏基于路径整合的导航，但尚无研究测试这些路径整合缺陷是否与头部方向（HD）细胞活动紊乱有关。因此，我们评估了在全身注射阿托品阻断毒蕈碱受体后，HD细胞在熟悉的场地中对视觉线索旋转的反应，以及在熟悉和新场地之间导航时的反应。阿托品处理降低了HD细胞的峰值放电率，但未能显著影响其他HD细胞放电特性。阿托品也未能显著破坏HD信号的主要地标控制，尽管我们使用了一种挑战这种地标控制的程序。相比之下，阿托品破坏了在熟悉和新场地之间导航时HD细胞的稳定性，在这种情况下，路径整合通常会在不同场地维持一致的HD细胞信号。这些结果表明，乙酰胆碱部分通过促进利用自身线索来维持方向的一致表征，从而有助于路径整合。（PsycINFO数据库记录）
