Cholinergic Boutons are Distributed Along the Dendrites and Somata of VIP Neurons in the Inferior Colliculus.
Cholinergic Boutons are Distributed Along the Dendrites and Somata of VIP Neurons in the Inferior Colliculus.
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胆碱能布顿沿下丘 VIP 神经元的树突和胞体分布。
DOI：
10.1007/s10162-022-00885-9
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Roberts,MichaelT
中科院分区：
文献类型：
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作者：
Kwapiszewski,JuliaT;Rivera-Perez,LuisM;Roberts,MichaelT
胆碱能信号在中枢听觉系统的中脑中枢下丘（IC）中塑造声音加工和可塑性，但胆碱能末端如何接触和影响IC中的单个神经元类型仍然未知。最近，我们利用药理学和电生理学的方法发现，乙酰胆碱通过激活α3β4*烟碱乙酰胆碱受体（nAChRs）来强烈激活IC中的一类谷氨酸能主神经元VIP神经元。在这里，我们证实并扩展了这些结果，使用的组织从老鼠的两性。首先，我们发现编码α3和β4nAChR亚基的mRNA在整个IC中的许多神经元中表达，包括大多数VIP神经元，这表明这些在大脑中罕见的亚基是IC中胆碱能信号传导的重要介质。接下来，通过结合VIP神经元的荧光标记和免疫荧光针对囊泡乙酰胆碱转运体（VAChT），我们发现，IC （ICc）中央核中的单个VIP神经元通过大量的胆碱能钮扣联系。胆碱能束分布在VIP神经元的体细胞附近和树突乔木的全长上，定位胆碱能信号，影响整个VIP神经元的体树突室产生的突触计算。此外，胆碱能扣偶尔也被观察到与VIP神经元上的树突棘密切相关，这增加了胆碱能信号也调节突触前释放到VIP神经元的可能性。综上所述，这些结果加强了胆碱能信号对视神经细胞和IC中其他神经元执行的听觉计算具有广泛影响的证据。
Cholinergic signaling shapes sound processing and plasticity in the inferior colliculus (IC), the midbrain hub of the central auditory system, but how cholinergic terminals contact and influence individual neuron types in the IC remains largely unknown. Using pharmacology and electrophysiology, we recently found that acetylcholine strongly excites VIP neurons, a class of glutamatergic principal neurons in the IC, by activating α3β4* nicotinic acetylcholine receptors (nAChRs). Here, we confirm and extend these results using tissue from mice of both sexes. First, we show that mRNA encoding α3and β4nAChR subunits is expressed in many neurons throughout the IC, including most VIP neurons, suggesting that these subunits, which are rare in the brain, are important mediators of cholinergic signaling in the IC. Next, by combining fluorescent labeling of VIP neurons and immunofluorescence against the vesicular acetylcholine transporter (VAChT), we show that individual VIP neurons in the central nucleus of the IC (ICc) are contacted by a large number of cholinergic boutons. Cholinergic boutons were distributed adjacent to the somata and along the full length of the dendritic arbors of VIP neurons, positioning cholinergic signaling to affect synaptic computations arising throughout the somatodendritic compartments of VIP neurons. In addition, cholinergic boutons were occasionally observed in close apposition to dendritic spines on VIP neurons, raising the possibility that cholinergic signaling also modulates presynaptic release onto VIP neurons. Together, these results strengthen the evidence that cholinergic signaling exerts widespread influence on auditory computations performed by VIP neurons and other neurons in the IC.