Neurotransmitter phenotypes of intermediate zone reticular formation projections to the motor trigeminal and hypoglossal nuclei in the rat
Neurotransmitter phenotypes of intermediate zone reticular formation projections to the motor trigeminal and hypoglossal nuclei in the rat
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DOI：
10.1002/cne.20604
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发表时间：
2005-07-18
影响因子：
2.5
通讯作者：
Travers, SP
中科院分区：
文献类型：
--
作者：
Travers, JB;Yoo, JE;Travers, SP
大量研究表明中间细胞（IRt）和微粒细胞（PCRt）网状形成（RF）在完全摄取反应中起重要作用。尽管IRt和PCRt包含大量投射到运动核的神经元，但RF的这些区域在神经递质表型方面是不均匀的。谷氨酸能、gaba能、胆碱能和氮能神经元均在PCRt和IRt中发现，但具有这些表型的神经元对运动三叉神经（mV）和舌下核（mXII）的投射尚未得到充分评估。在本研究中，将少量氟金（FG）注射到mV和mXII后，对切片进行免疫组织化学处理，检测逆行标记的FG神经元与一氧化氮合成酶（一氧化氮合酶）或乙酰胆碱（胆碱乙酰转移酶）的结合，或对GABA合成酶（GAD65/67）或脑膜谷氨酸囊泡转运蛋白（VGLUT2）的原位杂交。在另外三个病例中，在一个运动核中注射FG，在另一个运动核中注射霍乱毒素（亚基b），以确定双投射神经元的存在。MXII前运动神经元（pre-mXII）在IRt中高度集中。相比之下，在IRt和PCRt中，三叉神经前运动神经元（pre-mV）的比例几乎相等。高比例的运动前神经元VGLUT2阳性（pre-niXII: 68%; pre-mV: 53%），但gaba能投射分布差异较大，mV（25%）比mXII（8%）更大。显著的胆碱能和氮能神经元群体重叠于运动前神经元，但存在稀疏的双标记（< 10%）。IRt还包含高比例的神经元，投射到mV和MXII。IRt和PCRt中的这些不同类型的前运动神经元为舌肌和咀嚼肌的节律性激活提供了基础。(c) 2005 Wiley-Liss, Inc。
Numerous studies suggest an essential role for the intermediate (IRt) and parvocellular (PCRt) reticular formation (RF) in consummatory ingestive responses. Although the IRt and PCRt contain a large proportion of neurons with projections to the oromotor nuclei, these areas of the RF are heterogeneous with respect to neurotransmitter phenotypes. Glutamatergic, GABAergic, cholinergic, and nitrergic neurons are all found in the PCRt and IRt, but the projections of neurons with these phenotypes to the motor trigeminal (mV) and hypoglossal nucleus (mXII) has not been fully evaluated. In the present study, after small injections of Fluorogold (FG) into mV and mXII, sections were processed immunohistochemically to detect retrogradely labeled FG neurons in combination with the synthetic enzymes for nitric oxide (nitric oxide synthase) or acetylcholine (choline acetyltransferase) or in situ hybridization for the synthetic enzyme for GABA (GAD65/67) or the brainstern vesicular transporter for glutamate (VGLUT2). In three additional cases, FG injections were made into one motor nucleus and cholera toxin (subunit b) injected in the other to determine the presence of dual projection neurons. Premotor neurons to MXII (pre-mXII) were highly concentrated in the IRt. In contrast, there were nearly equal proportions of premotor-trigeminal neurons (pre-mV) in the IRt and PCRt. A high proportion of pre-oromotor neurons were positive for VGLUT2 (pre-niXII: 68%; pre-mV: 53%) but GABAergic projections were differentially distributed with a greater projection to mV (25%) compared to mXII (8%). Significant populations of cholinergic and nitrergic neurons overlapped pre-oromotor neurons, but there was sparse double-labeling (< 10%). The IRt also contained a high proportion of neurons that projected to both mV and MXII. These different classes of premotor neurons in the IRt and PCRt provide a substrate for the rhythmic activation of lingual and masticatory muscles. (c) 2005 Wiley-Liss, Inc.