Urethane, an anesthetic utilized for animal experiments, induces neocortical slow oscillations in which a large number of neurons emit rhythmic synchronized activity. However, it remains unclear how urethane affects neuronal activity in the hippocampus. In this study, we obtained in vivo patch-clamp recordings from dorsal hippocampal CA1 neurons in mice and found a reduction in the fluctuation of subthreshold membrane potentials during urethane anesthesia, implying reduced synaptic activity in the hippocampus. We then performed spike unit recordings from dorsal hippocampal CA1 neuronal ensembles in rats and found prominent reductions in the spike rates of the majority of hippocampal units, especially spatially selective units, during urethane anesthesia, whereas a subset of nonspatial units exhibited increased spike rates. The overall reductions in neuronal spike rates induced by urethane led to prominent decreases in spike synchronization across neuronal units. Consistently, the magnitude of hippocampal sharp wave ripples was also reduced by urethane. The suppression of hippocampal neuronal synchronization by urethane may lead to the disruption of offline memory reactivation mechanisms.

氨基甲酸乙酯是一种用于动物实验的麻醉剂，可诱导新皮质缓慢振荡，其中大量神经元发出有节奏的同步活动。然而，目前尚不清楚氨基甲酸乙酯如何影响海马中的神经元活动。在这项研究中，我们获得了体内来自小鼠背海马 CA1 神经元的膜片钳记录，发现在氨基甲酸乙酯麻醉期间阈下膜电位的波动减少，这意味着海马中的突触活动减少。然后，我们对大鼠背侧海马 CA1 神经元集合进行了尖峰单位记录，发现在氨基甲酸乙酯麻醉期间，大多数海马单位的尖峰率显着降低，尤其是空间选择性单元，而非空间单元的一个子集表现出增加的尖峰率。氨基甲酸乙酯引起的神经元尖峰速率的整体降低导致神经元单元之间尖峰同步的显着降低。一致地，氨基甲酸乙酯也降低了海马尖波涟漪的幅度。