Amygdalar Gating of Early Sensory Processing through Interactions with Locus Coeruleus
Amygdalar Gating of Early Sensory Processing through Interactions with Locus Coeruleus
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DOI：
10.1523/jneurosci.2797-16.2017
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发表时间：
2017-03-11
影响因子：
5.3
通讯作者：
McGann, John P.
中科院分区：
文献类型：
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作者：
Fast, Cynthia D.;McGann, John P.
据推测，恐惧和压力引起的杏仁核活动会通过杏仁核对神经调节中心的影响来影响感觉脑区域。为了直接检查这种关系，我们使用光学成像来观察小鼠杏仁核和蓝斑（LC）药理失活过程中嗅球抑制性中间神经元和嗅觉感觉神经元（嗅觉系统的初级感觉神经元，为大脑提供初始嗅觉输入）突触末端群体的气味诱发活动。尽管杏仁核不直接投射到嗅球，但杏仁核中央核、基底外侧核和外侧核的联合药理失活仍然强烈抑制了 OB 中 GABA 能抑制性中间神经元群体的气味诱发活性。通过灭活 LC 或用广谱去甲肾上腺素能受体拮抗剂预处理嗅球可以防止这种抑制。从嗅觉感觉神经元末梢到大脑嗅球的突触输出的可视化显示，杏仁核失活优先增强了来自鼻子的弱激活感觉传入群体的气味诱发的突触输出，从而证明了感觉门控的变化可能是由嗅觉感觉神经元末梢的局部抑制介导的。我们的结论是，杏仁核活动早在大脑的初级感觉输入时就通过调节去甲肾上腺素从蓝斑释放到嗅球来影响嗅觉处理。这些发现表明，杏仁核和 LC 状态主动决定选择哪些感觉信号在感觉脑区域进行处理。类似的局部电路在嗅觉、视觉和听觉系统中运行，这表明跨模式之间存在潜在的共享机制。
Fear-and stress-induced activity in the amygdala has been hypothesized to influence sensory brain regions through the influence of the amygdala on neuromodulatory centers. To directly examine this relationship, we used optical imaging to observe odor-evoked activity in populations of olfactory bulb inhibitory interneurons and of synaptic terminals of olfactory sensory neurons (the primary sensory neurons of the olfactory system, which provide the initial olfactory input to the brain) during pharmacological inactivation of amygdala and locus coeruleus (LC) in mice. Although the amygdala does not directly project to the olfactory bulb, joint pharmacological inactivation of the central, basolateral, and lateral nuclei of the amygdala nonetheless strongly suppressed odor-evoked activity in GABAergic inhibitory interneuron populations in the OB. This suppression was prevented by inactivation of LC or pretreatment of the olfactory bulb with a broad-spectrum noradrenergic receptor antagonist. Visualization of synaptic output from olfactory sensory neuron terminals into the olfactory bulb of the brain revealed that amygdalar inactivation preferentially strengthened the odor-evoked synaptic output of weakly activated populations of sensory afferents from the nose, thus demonstrating a change in sensory gating potentially mediated by local inhibition of olfactory sensory neuron terminals. Weconclude that amygdalar activity influences olfactory processing as early as the primary sensory input to the brain by modulating norepinephrine release from the locus coeruleus into the olfactory bulb. These findings show that the amygdala and LC state actively determines which sensory signals are selected for processing in sensory brain regions. Similar local circuitry operates in the olfactory, visual, and auditory systems, suggesting a potentially shared mechanism across modalities.