Nitrous oxide (N₂O), also called laughing gas, is used and abused recreationally worldwide. It has been found that long-term N₂O abuse impairs the central nervous system in humans, including the prefrontal cortex (PFC), which is a critical brain region involved in cognition. However, there is no ideal rodent model of laughing gas abuse. In the present study, we tested the impact of N₂O inhalation 12 h following its delivery on the behavioural responses of rats and the synaptic transmission properties of the medial prefrontal cortex (mPFC). We found that short-term (1 h/day for 1 day) inhalation of 40% N₂O had no significant effect on the performance of rats in the elevated plus maze test, light–dark transition test, tail suspension test, forced swim test, novel object recognition test, and social recognition test. However, long-term (1 h/day for 10 days) inhalation of 40% N₂O induced anxiety-like behaviour in the elevated plus maze test and light-dark transition test, but no abnormal performance was observed in the other four behavioural tests. In addition, long-term N₂O inhalation impaired long-term potentiation, but not basal synaptic transmission or the paired-pulse ratio, in the mPFC. These results demonstrate that long-term repeated N₂O inhalation induces anxiety-like behaviour and impairs synaptic plasticity in the mPFC of rats.

一氧化二氮 (N ₂ O)，也称为笑气，在世界范围内被娱乐性地使用和滥用。已经发现，长期滥用 N ₂ O 会损害人类的中枢神经系统，包括前额叶皮层 (PFC)，它是参与认知的关键大脑区域。然而，没有理想的笑气滥用啮齿动物模型。在本研究中，我们测试了 N ₂ O 吸入 12 小时后对大鼠行为反应和内侧前额叶皮层 (mPFC) 突触传递特性的影响。我们发现短期（1 小时/天持续 1 天）吸入 40% N ₂O对大鼠在高架加迷宫试验、明暗过渡试验、悬尾试验、强迫游泳试验、新物体识别试验和社会识别试验中的表现没有显着影响。但长期（1小时/天，共10天）吸入40% N ₂ O在高架十字迷宫试验和明暗过渡试验中诱发焦虑样行为，而其他四种行为均未观察到异常表现。测试。此外，长期吸入 N ₂ O 会损害 mPFC 中的长期增强，但不会损害基础突触传递或配对脉冲比。这些结果表明，长期反复吸入 N ₂ O 会诱发焦虑样行为并损害大鼠 mPFC 的突触可塑性。