Olfactory neural circuitry for attraction to amino acids revealed by transposon-mediated gene trap approach in zebrafish
Olfactory neural circuitry for attraction to amino acids revealed by transposon-mediated gene trap approach in zebrafish
复制标题
DOI：
10.1073/pnas.0900470106
复制
发表时间：
2009-06-16
影响因子：
11.1
通讯作者：
Yoshihara, Yoshihiro
中科院分区：
文献类型：
--
作者：
Koide, Tetsuya;Miyasaka, Nobuhiko;Yoshihara, Yoshihiro
在鱼类中，氨基酸是食物相关的重要嗅觉线索，以引起吸引力的反应。然而，这种嗅觉行为背后的神经回路并没有完全阐明。本研究应用Tol2转座子介导的基因诱捕技术对斑马鱼嗅觉系统进行了遗传学研究。建立了四种斑马鱼品系（SAGFF 27 A、SAGFF 91 B、SAGFF 179 A和SAGFF 228 C），其中修饰的转录激活因子Gal4FF在嗅觉感觉神经元（OSN）的不同亚群中表达。在嗅球（OB）中，个别线中的OSN将轴突投射到部分重叠但大部分不同的肾小球。在SAGFF 27 A中，Gal4FF主要在支配外侧肾小球簇的微绒毛OSN中表达，所述外侧肾小球簇对应于OB中的氨基酸响应区域。为了阐明嗅觉神经通路介导的摄食行为，我们在Gal4FF系中遗传表达破伤风神经毒素，以阻断不同群体肾小球中的突触传递，并检查其对氨基酸的行为反应。只有在携带破伤风神经毒素转基因的SAGFF27A鱼中，对氨基酸的吸引力反应才被取消。这些发现清楚地表明，微绒毛OSNs支配侧肾小球簇在氨基酸介导的摄食行为的斑马鱼的功能意义。因此，遗传学，神经解剖学和行为学相结合的方法使我们能够阐明成年斑马鱼各种嗅觉行为背后的神经回路机制。
In fish, amino acids are food-related important olfactory cues to elicit an attractive response. However, the neural circuit underlying this olfactory behavior is not fully elucidated. In the present study, we applied the Tol2 transposon-mediated gene trap method to dissect the zebrafish olfactory system genetically. Four zebrafish lines (SAGFF27A, SAGFF91B, SAGFF179A, and SAGFF228C) were established in which the modified transcription activator Gal4FF was expressed in distinct subsets of olfactory sensory neurons (OSNs). The OSNs in individual lines projected axons to partially overlapping but mostly different glomeruli in the olfactory bulb (OB). In SAGFF27A, Gal4FF was expressed predominantly in microvillous OSNs innervating the lateral glomerular cluster that corresponded to the amino acid-responsive region in the OB. To clarify the olfactory neural pathway mediating the feeding behavior, we genetically expressed tetanus neurotoxin in the Gal4FF lines to block synaptic transmission in distinct populations of glomeruli and examined their behavioral response to amino acids. The attractive response to amino acids was abolished only in SAGFF27A fish carrying the tetanus neurotoxin transgene. These findings clearly demonstrate the functional significance of the microvillous OSNs innervating the lateral glomerular cluster in the amino acid-mediated feeding behavior of zebrafish. Thus, the integrated approach combining genetic, neuroanatomical, and behavioral methods enables us to elucidate the neural circuit mechanism underlying various olfactory behaviors in adult zebrafish.