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

在小鼠中，陌生雄性的一些尿液信息素会阻止雌性怀孕，但交配雄性的信息素不会。交配的雄性无法破坏怀孕取决于他对雌性形成的信息素的记忆。信息素的记忆是通过犁鼻系统的第一中继--副嗅球（AOB）的神经变化实现的。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的显著的相互树-树突触。线粒体-颗粒细胞突触的长时程增强（LTP）被认为是信息素记忆的基础。在这项研究中，我表明，逆向刺激的二尖瓣细胞轴突诱导长时程增强（LTP）在二尖瓣颗粒细胞突触的AOB切片制备，和后期LTP是蛋白质合成依赖性的。我还研究了蛋白激酶M β假底物抑制肽（ZIP）的影响，它抑制LTP维持在海马和新皮层，在小鼠AOB突触LTP的晚期。结果表明，在AOB的突触LTP的维持依赖于ZIP敏感的机制。

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.