Neurogliaform neurons form a novel inhibitory network in the hippocampal CA1 area
Neurogliaform neurons form a novel inhibitory network in the hippocampal CA1 area
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DOI：
10.1523/jneurosci.1135-05.2005
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发表时间：
2005-07-20
影响因子：
5.3
通讯作者：
Capogna, M
中科院分区：
文献类型：
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作者：
Price, CJ;Cauli, B;Capogna, M
我们研究了CA1海马区腔隙分子层中的神经胶质样神经元。这些中间神经元具有短的星状树突和广泛的轴突，主要位于腔隙分子层。单细胞逆转录-聚合酶链式反应显示，这些神经元是GABA能的，大多数神经元表达神经肽Y的mRNA。大多数被测的神经胶质样神经元对α-肌动蛋白-2免疫反应阳性，许多陷窝分子间神经元共表达α-肌动蛋白-2和神经肽Y。神经胶质样神经元从穿支通路接受单突触的DNQX敏感的兴奋输入，40 Hz刺激该输入诱发EPSCs表现为抑制或初始促进，然后是抑制。在神经节状神经元之间进行的配对记录显示，85%的对是电连接的，70%的对也是通过GABA能突触连接的。在配对记录期间，将正弦波注入神经元，导致波形通过电突触传递。在5 Hz的刺激频率下，从神经节对记录到的整体性IPSCs容易疲劳，具有缓慢的衰变，并且对突触反应有强烈的抑制作用，该作用可被GABAB拮抗剂(2S)-3-[[(1S)-1-(3，4-二氯苯基)乙基]氨基-2-羟丙基](苯甲基)膦酸(CGP55845)所拮抗。CGP55845也使第一IPSC在5 Hz刺激时的波幅增加，提示突触传递受到紧张性抑制。还可以检测到由GABA(B)介导的小单位IPSC，这为GABA能中间神经元之间的这种成分提供了第一个证据。对突触内GABA(B1)亚单位的电子显微镜定位表明，该蛋白存在于突触前膜和突触后膜中。我们的数据揭示了一种新的神经元间网络，它非常适合于调节内嗅皮层和CA1海马区之间的信息流。
We studied neurogliaform neurons in the stratum lacunosum moleculare of the CA1 hippocampal area. These interneurons have short stellate dendrites and an extensive axonal arbor mainly located in the stratum lacunosum moleculare. Single-cell reverse transcription-PCR showed that these neurons were GABAergic and that the majority expressed mRNA for neuropeptide Y. Most neurogliaform neurons tested were immunoreactive for alpha-actinin-2, and many stratum lacunosum moleculare interneurons coexpressed alpha-actinin-2 and neuropeptide Y. Neurogliaform neurons received monosynaptic, DNQX-sensitive excitatory input from the perforant path, and 40 Hz stimulation of this input evoked EPSCs displaying either depression or initial facilitation, followed by depression. Paired recordings performed between neurogliaform neurons showed that 85% of pairs were electrically connected and 70% were also connected via GABAergic synapses. Injection of sine waveforms into neurons during paired recordings resulted in transmission of the waveforms through the electrical synapse. Unitary IPSCs recorded from neurogliaform pairs readily fatigued, had a slow decay, and had a strong depression of the synaptic response at a 5 Hz stimulation frequency that was antagonized by the GABAB antagonist (2S)-3-[[(1S)-1-(3,4-dichlorophenyl) ethyl] amino-2-hydroxypropyl](phenylmethyl) phosphinic acid (CGP55845). The amplitude of the first IPSC during the 5 Hz stimulation was also increased by CGP55845, suggesting a tonic inhibition of synaptic transmission. A small unitary GABA(B)-mediated IPSC could also be detected, providing the first evidence for such a component between GABAergic interneurons. Electron microscopic localization of the GABA(B1) subunit at neurogliaform synapses revealed the protein in both presynaptic and postsynaptic membranes. Our data disclose a novel interneuronal network well suited for modulating the flow of information between the entorhinal cortex and CA1 hippocampus.