Terminal nerve-derived neuropeptide Y modulates physiological responses in the olfactory epithelium of hungry axolotls (Ambystoma mexicanum)
Terminal nerve-derived neuropeptide Y modulates physiological responses in the olfactory epithelium of hungry axolotls (Ambystoma mexicanum)
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DOI：
10.1523/jneurosci.1977-06.2006
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发表时间：
2006-07-19
影响因子：
5.3
通讯作者：
Eisthen, Heather L.
中科院分区：
文献类型：
--
作者：
Mousley, Angela;Polese, Gianluca;Eisthen, Heather L.
脊椎动物的大脑主动调节传入的感觉信息，有效地过滤输入并将注意力集中在与动物的行为背景或生理状态最相关的环境刺激上。这种离心调制已被证明在视网膜和耳蜗的处理中发挥重要作用，但在嗅觉中受到的关注相对较少。终末神经是在嗅上皮周围的固有层下方延伸的颅神经，其解剖学和神经化学特征表明其调节嗅上皮中的活性。利用免疫细胞化学技术，我们表明，神经肽Y（NPY）是丰富的存在于末梢神经的蝾螈（Ambystoma mexicanum），水生蝾螈。由于神经肽Y在调节食欲和饥饿在许多脊椎动物中起着重要的作用，我们调查的可能性，神经肽Y调节活动的嗅觉上皮有关的动物的饥饿水平。因此，我们的特点是全长神经肽Y基因从蝾螈，使真正的蝾螈神经肽Y的合成用于电生理实验。我们发现，蝾螈神经肽Y调节嗅觉上皮的反应引起的L-谷氨酸，食物相关的气味，但只有在饥饿的动物。同样，全细胞膜片钳记录表明，浴应用美西螈神经肽Y增强河豚毒素敏感的内向电流的幅度，但仅在饥饿的动物。这些结果表明，在嗅觉上皮中的NPY受体的表达或活性可能会随着饥饿水平而改变，并且末端神经源性肽调节嗅觉上皮中的活性以响应动物的行为和生理情况的变化。
The vertebrate brain actively regulates incoming sensory information, effectively filtering input and focusing attention toward environmental stimuli that are most relevant to the animal's behavioral context or physiological state. Such centrifugal modulation has been shown to play an important role in processing in the retina and cochlea, but has received relatively little attention in olfaction. The terminal nerve, a cranial nerve that extends underneath the lamina propria surrounding the olfactory epithelium, displays anatomical and neurochemical characteristics that suggest that it modulates activity in the olfactory epithelium. Using immunocytochemical techniques, we demonstrate that neuropeptide Y (NPY) is abundantly present in the terminal nerve in the axolotl (Ambystoma mexicanum), an aquatic salamander. Because NPY plays an important role in regulating appetite and hunger in many vertebrates, we investigated the possibility that NPY modulates activity in the olfactory epithelium in relation to the animal's hunger level. We therefore characterized the full-length NPY gene from axolotls to enable synthesis of authentic axolotl NPY for use in electrophysiological experiments. We find that axolotl NPY modulates olfactory epithelial responses evoked by L-glutamic acid, a food-related odorant, but only in hungry animals. Similarly, whole-cell patch-clamp recordings demonstrate that bath application of axolotl NPY enhances the magnitude of a tetrodotoxin-sensitive inward current, but only in hungry animals. These results suggest that expression or activity of NPY receptors in the olfactory epithelium may change with hunger level, and that terminal nerve-derived peptides modulate activity in the olfactory epithelium in response to an animal's changing behavioral and physiological circumstances.