Modulatory effect of ionizing radiation on food-NaCl associative learning:: the role of γ subunit of G protein in Caenorhabditis elegans
Modulatory effect of ionizing radiation on food-NaCl associative learning:: the role of γ subunit of G protein in Caenorhabditis elegans
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DOI：
10.1096/fj.07-9259com
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发表时间：
2008-03-01
期刊：
影响因子：
4.8
通讯作者：
Kobayashi, Yasuhiko
中科院分区：
文献类型：
--
作者：
Sakashita, Tetsuya;Hamada, Nobuyuki;Kobayashi, Yasuhiko
已知电离辐射（IR）通过抑制海马中的成年神经发生而损害学习。然而，在一个成熟的神经系统，IR诱导的功能改变是独立的神经发生仍然在很大程度上是未知的。在本研究中，我们分析了IR对成年秀丽隐杆线虫不经历神经发生的食物-NaCl联想学习范式的影响。我们观察到，减少对氯化钠的趋化性发生后，结合饥饿和暴露于氯化钠。暴露于IR诱导一个额外的减少趋化性后立即急性剂量的过渡阶段的食物-NaCl的联想学习。令人惊讶的是，慢性照射在暴露的动物中诱导负趋化性，即，主要的回避反应。IR诱导的额外减少趋化性急性和慢性照射后显着抑制gpc-1突变体，这是有缺陷的GPC-1（异源三聚体G蛋白的两个γ亚基之一）。在食物-NaCl联想学习过程中，IR对cAMP的趋化性有影响，但对赖氨酸和苯甲醛的趋化性无影响。我们的新发现表明，IR行为作为一个调制器的食物-NaCl通过线虫GPC-1和一个特定的神经元网络的关联学习，并可能揭示IR对学习的调节作用。
Ionizing radiation (IR) is known to impair learning by suppressing adult neurogenesis in the hippocampus. However, in a mature nervous system, IR-induced functional alterations that are independent of neurogenesis remain largely unknown. In the present study, we analyzed the effects of IR on a food-NaCl associative learning paradigm of adult Caenorhabditis elegans that does not undergo neurogenesis. We observed that a decrease in chemotaxis toward NaCl occurs only after combined starvation and exposure to NaCl. Exposure to IR induced an additional decrease in chemotaxis immediately after an acute dose in the transition stage of the food-NaCl associative learning. Strikingly, chronic irradiation induced negative chemotaxis in the exposed animals, i.e., the primary avoidance response. IR-induced additional decreases in chemotaxis after acute and chronic irradiation were significantly suppressed in the gpc-1 mutant, which was defective in GPC-1 (one of the two gamma subunits of the heterotrimeric G-protein). Chemotaxis to cAMP, but not to lysine and benzaldehyde, was influenced by IR during the food-NaCl associative learning. Our novel findings suggest that IR behaves as a modulator in the food-NaCl associative learning via C elegans GPC-1 and a specific neuronal network and may shed light on the modulatory effect of IR on learning.