Pak Alexandr, Chubykin Alexander A
Department of Biological Sciences, Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA.
Cereb Cortex Commun. 2020;1(1):tgaa066. doi: 10.1093/texcom/tgaa066. Epub 2020 Sep 16.
Serotonin (5-hydroxytryptamine) is crucial for the proper development of neuronal circuits early in life and their refinement throughout adulthood. Its signaling is tightly regulated by the serotonin transporter (SERT), alterations of which were implicated in various neurological and psychiatric disorders. Animal models lacking a functional SERT variant display diverse phenotypes, including increased anxiety, social communication deficits, and altered cortical development. However, it remains unclear how SERT disruption affects sensory processing and experience-dependent learning in adulthood. It has been previously shown that perceptual experience leads to the development of visual familiarity-evoked theta oscillations in mouse V1. Here, we discovered that familiarity-evoked theta oscillations were longer and less stimulus specific in SERT knockout (KO) compared with wild-type (WT) mice. Interestingly, while the overall visual response properties were similar in naive mice, orientation and spatial frequency processing were significantly impaired in SERT KO compared with WT or SERT heterozygous mice following perceptual experience. Our findings shed more light on the mechanism of familiarity-evoked oscillations and highlight the importance of serotonin signaling in perceptual learning.
血清素（5-羟色胺）对于生命早期神经回路的正常发育以及成年期神经回路的优化至关重要。其信号传导受到血清素转运体（SERT）的严格调控，SERT的改变与多种神经和精神疾病有关。缺乏功能性SERT变体的动物模型表现出多种表型，包括焦虑增加、社交沟通缺陷和皮质发育改变。然而，目前尚不清楚SERT破坏如何影响成年期的感觉处理和经验依赖性学习。此前已有研究表明，感知经验会导致小鼠初级视觉皮层（V1）中出现视觉熟悉诱发的theta振荡。在此，我们发现，与野生型（WT）小鼠相比，SERT基因敲除（KO）小鼠中熟悉诱发的theta振荡持续时间更长且对刺激的特异性更低。有趣的是，虽然未接触过刺激的小鼠的整体视觉反应特性相似，但在经历感知经验后，与WT或SERT杂合小鼠相比，SERT KO小鼠的方向和空间频率处理能力明显受损。我们的研究结果进一步揭示了熟悉诱发振荡的机制，并强调了血清素信号在感知学习中的重要性。
