Noradrenaline-induced enhancement of oscillatory local field potentials in the mouse accessory olfactory bulb does not depend on disinhibition of mitral cells.
Noradrenaline-induced enhancement of oscillatory local field potentials in the mouse accessory olfactory bulb does not depend on disinhibition of mitral cells.
复制标题
去甲肾上腺素诱导的小鼠副嗅球振荡局部场电位的增强并不依赖于二尖瓣细胞的去抑制。
DOI：
10.1111/j.1460-9568.2012.08070.x
复制
发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Leszkowicz E
中科院分区：
文献类型：
--
作者：
Leszkowicz E
嗅球与其他脑区的不同之处在于它在树-树相互突触上使用双向突触传递。在犁鼻处理的第一阶段，这些相互突触提供了从颗粒细胞中间神经元到副嗅球（AOB）中的二尖瓣细胞投射神经元的抑制反馈的紧密耦合。已经提出，mGluR 2激动剂DCG-IV和去甲肾上腺素都通过减少对二尖瓣细胞的GABA能反馈来促进配偶识别记忆的形成。由此产生的二尖瓣细胞去抑制被认为诱导从颗粒到二尖瓣细胞的抑制反馈增益的持久增强，这选择性地门控学习的化学感觉信息的传输。然而，我们发现局部输注去甲肾上腺素和DCG-IV均未能解除氨基甲酸乙酯麻醉小鼠中的AOB神经活性。DCG-IV输注与GABA A激动剂异谷瓦辛具有相似的作用，表明其增加而不是减少AOB中的GABA能抑制。尽管诱导AOB局部场电位功率的长期增加，但向AOB中输注去甲肾上腺素也未能解除清醒小鼠的二尖瓣细胞抑制，这与记忆形成后观察到的结果相似。这些结果表明，僧帽细胞抑制解除对于小鼠配偶识别记忆形成的AOB神经变化并不是必需的。
The olfactory bulb differs from other brain regions by its use of bidirectional synaptic transmission at dendrodendritic reciprocal synapses. These reciprocal synapses provide tight coupling of inhibitory feedback from granule cell interneurons to mitral cell projection neurons in the accessory olfactory bulb (AOB), at the first stage of vomeronasal processing. It has been proposed that both the mGluR2 agonist DCG‐IV and noradrenaline promote mate recognition memory formation by reducing GABAergic feedback on mitral cells. The resultant mitral cell disinhibition is thought to induce a long‐lasting enhancement in the gain of inhibitory feedback from granule to mitral cells, which selectively gates the transmission of the learned chemosensory information. However, we found that local infusions of both noradrenaline and DCG‐IV failed to disinhibit AOB neural activity in urethane‐anaesthetised mice. DCG‐IV infusion had similar effects to the GABAAagonist isoguvacine, suggesting that it increased GABAergic inhibition in the AOB rather than reducing it. Noradrenaline infusion into the AOB also failed to disinhibit mitral cells in awake mice despite inducing long‐term increases in power of AOB local field potentials, similar to those observed following memory formation. These results suggest that mitral cell disinhibition is not essential for the neural changes in the AOB that underlie mate recognition memory formation in mice.