Fast Synaptic Currents in Drosophila Mushroom Body Kenyon Cells Are Mediated by α-Bungarotoxin-Sensitive Nicotinic Acetylcholine Receptors and Picrotoxin-Sensitive GABA Receptors
Fast Synaptic Currents in Drosophila Mushroom Body Kenyon Cells Are Mediated by α-Bungarotoxin-Sensitive Nicotinic Acetylcholine Receptors and Picrotoxin-Sensitive GABA Receptors
复制标题
果蝇蘑菇体 Kenyon 细胞中的快速突触电流由 α-银环蛇毒素敏感的烟碱乙酰胆碱受体和印防毒素敏感的 GABA 受体介导
作者：
Hailing Su;D. O'Dowd
蘑菇体是昆虫大脑中的一个对称区域，在嗅觉联想学习中起着重要的作用。果蝇中的遗传研究表明，作为记忆获得和存储基础的可塑性发生在蘑菇体Kenyon细胞的树突上的突触处（Dubnau等人，2001年）。对这些方面的嗅觉联想学习的突触可塑性机制的进一步探索需要鉴定介导Kenyon细胞中快速突触传递的受体。为此，我们开发了一种培养系统，支持形成兴奋性和抑制性突触之间的连接神经元收获的中央大脑区域的后期阶段果蝇puppueros。在来自OK 107-GAL 4;UAS-GFP质粒的培养物中，蘑菇体Kenyon细胞被鉴定为小直径、绿色荧光蛋白阳性（GFP+）神经元。在GFP+ Kenyon细胞中，快速EPSC由α-银环蛇毒素敏感性烟碱乙酰胆碱受体（nAChR）介导。微型EPSC具有快速的上升和衰减动力学和广泛的，正偏的振幅分布。快速IPSC由印苦毒敏感的氯离子传导GABA受体介导。微型IPSC还具有快速的上升和衰减速率以及宽的幅度分布。培养的Kenyon细胞中的绝大多数自发突触电流由α-银环蛇毒素敏感的nAChR或印防己毒素敏感的GABA受体介导。因此，这些受体也可能介导体内Kenyon细胞的突触传递，并有助于嗅觉联想学习过程中的可塑性。
The mushroom bodies, bilaterally symmetric regions in the insect brain, play a critical role in olfactory associative learning. Genetic studies in Drosophila suggest that plasticity underlying acquisition and storage of memory occurs at synapses on the dendrites of mushroom body Kenyon cells (Dubnau et al., 2001). Additional exploration of the mechanisms governing synaptic plasticity contributing to these aspects of olfactory associative learning requires identification of the receptors that mediate fast synaptic transmission in Kenyon cells. To this end, we developed a culture system that supports the formation of excitatory and inhibitory synaptic connections between neurons harvested from the central brain region of late-stage Drosophila pupae. Mushroom body Kenyon cells are identified as small-diameter, green fluorescent protein-positive (GFP+) neurons in cultures from OK107-GAL4;UAS-GFP pupae. In GFP+ Kenyon cells, fast EPSCs are mediated by α-bungarotoxin-sensitive nicotinic acetylcholine receptors (nAChRs). The miniature EPSCs have rapid rise and decay kinetics and a broad, positively skewed amplitude distribution. Fast IPSCs are mediated by picrotoxin-sensitive chloride conducting GABA receptors. The miniature IPSCs also have a rapid rate of rise and decay and a broad amplitude distribution. The vast majority of spontaneous synaptic currents in the cultured Kenyon cells are mediated byα-bungarotoxin-sensitive nAChRs or picrotoxin-sensitive GABA receptors. Therefore, these receptors are also likely to mediate synaptic transmission in Kenyon cells in vivo and to contribute to plasticity during olfactory associative learning.