Laboratorio de Neurofisiología Experimental, Centro de Investigación Biomédica de Michoacán, Instituto Mexicano del Seguro Social, Morelia, México,
Exp Brain Res. 2013 Oct;230(4):407-26. doi: 10.1007/s00221-013-3679-x. Epub 2013 Aug 30.
Hippocampal theta activity is the result of the concerted activity of a group of nuclei located in the brain stem and the caudal diencephalic area, which are together referred to as the synchronizing ascending system. Serotonin is recognized as the only neurotransmitter able to desynchronize the hippocampal electroencephalographic. A theory has been developed in which serotonin, acting on medial septal neurons, modulates cholinergic/GABAergic inputs to the hippocampus and, thus, the cognitive processing mediated by this area. However, few studies have addressed the relationship between serotonin modulation of theta activity and cognition. In this review, we present a summary and analysis of the data relating serotonin and its theta activity modulation with cognition, and we also discuss the few works relating serotonin, theta activity and cognition as well as the theories regarding the serotonin regulation of memory processes organized by the hippocampus. We propose that serotonin depletion induces impairment of the relays coding the frequency of hippocampal theta activity, whereas depletion of the relays in which frequency is not coded induces improvements in spatial learning that are related to increased expression of high-frequency theta activity.
海马体θ活动是位于脑干和尾状丘脑区域的一组核团协同活动的结果，这些核团被统称为同步上升系统。血清素被认为是唯一能够使海马体脑电图去同步化的神经递质。已经提出了一种理论，即血清素作用于隔核神经元，调节海马体的胆碱能/GABA 能输入，从而调节该区域介导的认知加工。然而，很少有研究涉及到血清素对θ活动的调制与认知之间的关系。在这篇综述中，我们总结和分析了与认知有关的血清素及其θ活动调制的数据，还讨论了与血清素、θ活动和认知有关的少量工作，以及关于海马体记忆过程的血清素调节的理论。我们提出，血清素耗竭会损害编码海马体θ活动频率的中继，而不编码频率的中继耗竭会导致空间学习的改善，这与高频θ活动表达的增加有关。
