Metabotropic γ-aminobutyric acid (GABAB) receptors modulate feeding behavior in the calcisponge Leucandra aspera.
Metabotropic γ-aminobutyric acid (GABAB) receptors modulate feeding behavior in the calcisponge Leucandra aspera.
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DOI：
10.1002/jez.657
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发表时间：
2011-03
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影响因子：
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通讯作者：
P. Ramoino;Fabio D. Ledda;S. Ferrando;L. Gallus;P. Bianchini;A. Diaspro;M. Fato;G. Tagliafierro;R. Manconi
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文献类型：
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作者：
P. Ramoino;Fabio D. Ledda;S. Ferrando;L. Gallus;P. Bianchini;A. Diaspro;M. Fato;G. Tagliafierro;R. Manconi
在这里，我们报告的γ-氨基丁酸（GABA）能系统中的calcisponge Leucandra aspera的存在，并检查该系统的组件，包括GABA样受体的细胞定位使用免疫荧光和共聚焦显微镜。此外，我们第一次证明了GABA作为信使在调节海绵喂养行为中起着功能性作用。我们发现，GABA（B）R1和R2亚基存在于海绵的后囊细胞以及内、后囊细胞中。GABA在这种海绵的摄食行为中的功能作用进行了测试。GABA受体参与L.用与德克萨斯红缀合的葡聚糖作为材料摄取的标记物，并通过用GABA（B）受体激动剂和拮抗剂处理分离的海绵细胞，证明了aspera的细胞毒性。当使用GABA（B）受体激动剂巴氯芬时，在解离的海绵细胞中摄取的葡聚糖的量增加，并且这种刺激作用通过用GABA（B）受体拮抗剂法氯芬治疗来防止。巴氯芬对摄取的影响被百日咳毒素阻断，从而表明G蛋白在调节L.阿斯佩拉。此外，我们发现的证据表明，GABA受体参与海绵细胞的溶解有机物的消耗。这些发现表明，GABA受体及其功能作用在动物王国前神经系统进化中是高度保守的特征。
Here, we report the presence of the γ-aminobutyric acid (GABA)-ergic system in the calcisponge Leucandra aspera and examine the cellular localization of the components of this system, including GABA-like receptors using immunofluorescence and confocal microscopy. Furthermore, we demonstrate for the first time that GABA plays a functional role as a messenger in regulating sponge-feeding behavior. We found that both GABA(B) R1 and R2 subunits are present in the choanocytes of sponges as well as in the eso- and endopinacocytes. The functional role of GABA in the feeding behavior of this sponge was tested. The involvement of GABA receptors in the endocytic processes in L. aspera was demonstrated with dextran conjugated to Texas Red as a marker for material ingestion and by treating isolated sponge cells with a GABA(B) receptor agonist and an antagonist. The amount of dextran that was ingested increased in dissociated sponge cells when the GABA(B) receptor agonist baclofen was used, and this stimulatory effect was prevented by treatment with the GABA(B) receptor antagonist phaclofen. The baclofen effect on uptake was blocked by treatment with pertussis toxin, thus indicating a role for G proteins in modulating feeding behavior in L. aspera. Moreover, we found evidence that GABA receptors are involved in the consumption of dissolved organic matter by sponge cells. These findings suggest that GABA receptors and their functional role are highly conservative traits in the animal kingdom prenervous system evolution.