Mechanisms of synaptic plasticity at the single neuron level for understanding a pheromonal memory stored in the mouse accessory olfactory bulb.

在老鼠身上，不熟悉的雄性的一些尿信息素会阻止雌性怀孕，但交配雄性的尿信息素不会。交配的雄性无法破坏怀孕取决于雌性对他的信息素形成的记忆。信息素记忆的基础是副嗅球（AOB）的神经变化，它是颏鼻系统中的第一个中继。AOB中的微电路包括二尖瓣细胞、一类投射神经元和颗粒细胞中间神经元之间显著的互反树突突触。二尖粒到颗粒细胞突触的长期增强（LTP）被认为是信息素记忆的基础。在这项研究中，我发现在AOB切片制备中，二尖瓣细胞轴突的反向刺激诱导二尖瓣到颗粒细胞突触的长期增强（LTP），并且后期LTP依赖于蛋白质合成。我还检查了蛋白激酶Mζ伪底物抑制肽（ZIP）的作用，它抑制海马和新皮层中LTP的维持，对小鼠AOB突触中LTP的晚期阶段的影响。结果表明，AOB突触LTP的维持依赖于zip敏感机制。

In mice, some urinary pheromones of the unfamiliar male block pregnancy of the female, but those of the mating male do not. The inability of the mating male to disrupt the pregnancy depends on the memory of his pheromones formed by the female. The pheromonal memory is based on the neural changes in the accessory olfactory bulb (AOB), the first relay in the vomeronasal system. Microcircuits in the AOB include the prominent reciprocal dendrodendritic synapse between mitral cells, a single class of projection neurons, and granule cell interneurons. Long-term potentiation (LTP) at the mitral-to-granule cell synapse is expected to underlie the pheromonal memory. In this study I showed that antidromic stimulation of mitral cell axons induces long-term potentiation (LTP) at the mitral-to-granule cell synapse in slice preparations of the AOB, and that the late-phase LTP is protein synthesis-dependent. I also examined the effects of a protein kinase Mζ pseudosubstrate inhibitory peptide (ZIP), which inhibits LTP maintenance in the hippocampus and the neocortex, on the late phase of LTP at synapses in the mouse AOB. The results indicate that the maintenance of LTP at synapses in the AOB depends on ZIP-sensitive mechanisms.