常春藤細(xì)胞的命名是由于該細(xì)胞異常密集曲折的軸突形狀,，十分類似多雨英倫三島豐富的常春藤植物,。令人奇怪的是,，盡管常春藤細(xì)胞具有獨(dú)特的細(xì)胞形態(tài),，但至今還沒有被確定為一類不同的細(xì)胞類型,。在3月27日的《神經(jīng)元》（Neuron）雜志上，F(xiàn)uentealba等人就常春藤細(xì)胞的特點(diǎn)展開研究,。實(shí)驗(yàn)證明,，常春藤細(xì)胞有著相當(dāng)豐富的GABA能細(xì)胞類型的海馬神經(jīng)元，在低頻率下有寬電位,，能夠在錐體細(xì)胞中引起緩慢GABA能細(xì)胞受體介導(dǎo)的反應(yīng)，并有可能利用突觸前后機(jī)制提供從CA3到CA1的穩(wěn)態(tài)調(diào)節(jié),。
在大腦皮質(zhì)中,， GABA能中間神經(jīng)元往往被視為快速反應(yīng)細(xì)胞。最新研究發(fā)現(xiàn),，常春藤細(xì)胞是一類反應(yīng)緩慢的神經(jīng)元細(xì)胞,，它們較為密集，有精密的軸突支配著大多數(shù)的基底和斜錐體細(xì)胞樹突,。常春藤細(xì)胞表達(dá)一氧化氮合成酶,、神經(jīng)肽Y和高水平的GABA能細(xì)胞受體α1亞基；這類細(xì)胞在體內(nèi)的低頻范圍內(nèi)具有寬電位,，但具有獨(dú)特相位鎖定,，從而在行為上與神經(jīng)網(wǎng)絡(luò)節(jié)律包括8、γ和波紋振動(dòng)等相關(guān)聯(lián),。
在體外,，成對(duì)的記錄顯示，常春藤細(xì)胞獲得由錐體細(xì)胞抑制的EPSP合成酶，然后錐體細(xì)胞獲得了由常春藤細(xì)胞緩慢且漸漸衰退抑制輸入信號(hào),。相反,，快速反應(yīng)的中間神經(jīng)元細(xì)胞正在以毫秒級(jí)精度活動(dòng)；相當(dāng)多的常春藤細(xì)胞表達(dá)出突觸前神經(jīng)元調(diào)節(jié)器,，并通過緩慢和逐漸衰退的GABA能輸入調(diào)節(jié)錐體細(xì)胞樹突的興奮度,。（科學(xué)網(wǎng) 武彥文/編譯）
生物谷推薦原始出處：
（Neuron），Vol 57, 917-929, 27 March 2008,，Pablo Fuentealba, Thomas Klausberger
Ivy Cells: A Population of Nitric-Oxide-Producing, Slow-Spiking GABAergic Neurons and Their Involvement in Hippocampal Network Activity
Pablo Fuentealba,1 Rahima Begum,2 Marco Capogna,1 Shozo Jinno,1,3 László F. Márton,1,4 Jozsef Csicsvari,1 Alex Thomson,2 Peter Somogyi,1 and Thomas Klausberger1,5,
1 MRC Anatomical Neuropharmacology Unit, Oxford University, Oxford OX1 3TH, UK
2 Department of Pharmacology, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, UK
3 Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan
4 Neural Systems Research Group, Faculty of Engineering, EMTE-Sapientia Hungarian University of Transylvania, RO-540485 Targu Mures, Romania
5 Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria
Summary
In the cerebral cortex, GABAergic interneurons are often regarded as fast-spiking cells. We have identified a type of slow-spiking interneuron that offers distinct contributions to network activity. “Ivy” cells, named after their dense and fine axons innervating mostly basal and oblique pyramidal cell dendrites, are more numerous than the parvalbumin-expressing basket, bistratified, or axo-axonic cells. Ivy cells express nitric oxide synthase, neuropeptide Y, and high levels of GABAA receptor α1 subunit; they discharge at a low frequency with wide spikes in vivo, yet are distinctively phase-locked to behaviorally relevant network rhythms including theta, gamma, and ripple oscillations. Paired recordings in vitro showed that Ivy cells receive depressing EPSPs from pyramidal cells, which in turn receive slowly rising and decaying inhibitory input from Ivy cells. In contrast to fast-spiking interneurons operating with millisecond precision, the highly abundant Ivy cells express presynaptically acting neuromodulators and regulate the excitability of pyramidal cell dendrites through slowly rising and decaying GABAergic inputs.
