Faculty of Psychology, Chair of Lifespan Developmental Neuroscience, TU Dresden, 01062 Dresden, Germany.
Department of Psychiatry, TU Dresden, 01307 Dresden, Germany.
Cereb Cortex. 2023 Nov 27;33(23):11247-11256. doi: 10.1093/cercor/bhad361.
Accumulated evidence from animal studies suggests a role for the neuromodulator dopamine in memory processes, particularly under conditions of novelty or reward. Our understanding of how dopaminergic modulation impacts spatial representations and spatial memory in humans remains limited. Recent evidence suggests age-specific regulation effects of dopamine pharmacology on activity in the medial temporal lobe, a key region for spatial memory. To which degree this modulation affects spatially patterned medial temporal representations remains unclear. We reanalyzed recent data from a pharmacological dopamine challenge during functional brain imaging combined with a virtual object-location memory paradigm to assess the effect of Levodopa, a dopamine precursor, on grid-like activity in the entorhinal cortex. We found that Levodopa impaired grid cell-like representations in a sample of young adults (n = 55, age = 26-35 years) in a novel environment, accompanied by reduced spatial memory performance. We observed no such impairment when Levodopa was delivered to participants who had prior experience with the task. These results are consistent with a role of dopamine in modulating the encoding of novel spatial experiences. Our results suggest that dopamine signaling may play a larger role in shaping ongoing spatial representations than previously thought.
动物研究的积累证据表明，神经调质多巴胺在记忆过程中起作用，特别是在新奇或奖励的情况下。我们对多巴胺调制如何影响人类的空间表示和空间记忆的理解仍然有限。最近的证据表明，多巴胺药理学对内侧颞叶活动的年龄特异性调节作用，内侧颞叶是空间记忆的关键区域。这种调制在多大程度上影响空间模式化的内侧颞叶表示仍然不清楚。我们重新分析了最近在功能脑成像期间进行的药物多巴胺挑战的相关数据，该挑战与虚拟物体位置记忆范式相结合，以评估左旋多巴（多巴胺前体）对内侧颞叶网格细胞样活动的影响。我们发现，在一个新环境中，左旋多巴在年轻成年人（n=55，年龄为 26-35 岁）的样本中损害了网格细胞样表示，同时空间记忆表现也下降了。当左旋多巴给予对任务有先验经验的参与者时，我们没有观察到这种损害。这些结果与多巴胺在调节新的空间体验的编码中的作用一致。我们的结果表明，多巴胺信号可能在塑造正在进行的空间表示方面比以前认为的更为重要。
