Group II metabotropic glutamate receptors are differentially expressed in the medial nucleus of the trapezoid body in the developing and adult rat
Group II metabotropic glutamate receptors are differentially expressed in the medial nucleus of the trapezoid body in the developing and adult rat
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DOI：
10.1016/s0306-4522(01)00080-x
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发表时间：
2001-01-01
期刊：
影响因子：
3.3
通讯作者：
Grandes, P
中科院分区：
文献类型：
--
作者：
Elezgarai, I;Bilbao, A;Grandes, P
通过激活神经胶质细胞中表达的神经递质受体的神经元-神经胶质信号传导的存在是有据可查的。在兴奋性突触中，从突触前末梢释放的谷氨酸不仅激活突触后受体，而且激活位于包裹突触的胶质细胞中的亲离子型和亲代谢型谷氨酸受体。听觉系统斜方体内侧核参与声音在空间中的定位。在这个核中，由主球形细胞体上的赫尔德萼形成的大的兴奋性突触终末被星形胶质细胞突起包裹。由于这些突触是从出生后的早期功能，神经胶质细胞接受兴奋性突触信号从盏可能参与调节系统的成熟和development. GroupsI和II的代谢型谷氨酸受体（mGluRs）已被定位在不同的大脑区域的胶质细胞。为了研究第二组mGluRs是否存在于斜方体的内侧核中，我们通过免疫细胞化学方法研究了mGluR 2/3在发育和成熟核中的表达模式。最显着的发现是开关的发生mGluR 2/3从神经胶质细胞到神经元隔室。因此，在出生后早期发育期间，在Held肾盏周围的星形胶质细胞突起中观察到mGluR 2/3免疫反应性的优先定位。与此相反，在成年大鼠的主要特点是存在的第二组mGluRs在突触前萼的举行和突触后的主要球形celles.From这些观察，我们建议的作用，第二组mGluRs在神经胶质细胞信号的萼举行的主要球形神经元突触。这些受体的激活可能与斜方体内侧核内突触传递的成熟和调节有关。(C)2001年IBRO。由爱思唯尔科技有限公司出版。保留所有权利。
The existence of a neuronal-glial signalling through the activation of neurotransmitter receptors expressed in glia is well-documented. In excitatory synapses, glutamate released from presynaptic terminals activates not only postsynaptic receptors, but also ionotropic and metabotropic glutamate receptors localized in the glia ensheathing the synapses. The medial nucleus of the trapezoid body of the auditory system is involved in the localization of sounds in the space. In this nucleus, the large excitatory synaptic terminals formed by the calyces of Held on the principal globular cell bodies are wrapped by astrocytic processes. Since these synapses are functional from early postnatal days, glia receiving excitatory synaptic signals from the calyces may participate in modulating the maturation and development of the system.Groups I and II of metabotropic glutamate receptors (mGluRs) have been localized in glial cells in different brain regions. To investigate whether group II mGluRs are present in the medial nucleus of the trapezoid body, we have studied the pattern of expression of mGluR2/3 in the developing and mature nucleus by means of immunocytochemical methods. The most remarkable finding was the switch in the occurrence of mGluR2/3 from glial to neuronal compartments. Thus, a preferential localization of mGluR2/3 immunoreactivity was observed in astrocytic processes surrounding the calyces of Held during the early postnatal development. In contrast, the main feature in adult rats was the presence of the group II mGluRs in presynaptic calyces of Held and postsynaptic principal globular cells.From these observations we suggest a role for group II mGluRs in neuronal-glial signalling in the calyx of Held-principal globular neuron synapses. Activation of these receptors might be relevant to the maturation and modulation of synaptic transmission in the medial nucleus of the trapezoid body. (C) 2001 IBRO. Published by Elsevier Science Ltd. All rights reserved.