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

在小鼠身上，一些陌生雄性的尿液信息素会阻止雌性受孕，但交配的雄性不会。交配的雄性不能破坏怀孕取决于雌性对其信息素的记忆。信息素记忆是基于副嗅球(AOB)的神经变化，副嗅球是犁鼻系统的第一个中继器。AOB内的微回路包括二尖瓣细胞、单类投射神经元和颗粒细胞中间神经元之间显著的树-树突触。二尖瓣到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，我证明了逆行刺激二尖瓣细胞轴突诱导AOB切片上二尖瓣到颗粒细胞突触的长时程增强(LTP)，并且晚期LTP是蛋白质合成依赖的。我还检测了一种蛋白激酶Mζ假底物抑制肽(ZIP)对小鼠AOB突触的LTP晚期的影响。结果表明，AOB内突触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.