研究人员发现，厌恶信息是由环绕蘑菇体（MB）的鞘状神经胶质（EG）传递的。冲击会诱导EG的谷氨酸囊泡外排。阻断胞吐作用会损害厌恶学习，而在条件反射过程中激活EG则可以取代厌恶刺激。从EG释放的谷氨酸与MB中的N-甲基-D-天冬氨酸受体结合，但由于Mg2+的阻断，只有当果蝇同时接触到气味时才会发生Ca2+的流入。EG的囊泡外排也会诱导休克相关的多巴胺释放，这在防止形成不适当的联想方面发挥了作用。
这些结果表明，EG释放的囊泡谷氨酸可传递联想学习所需的负效信息。
研究人员表示，在果蝇的厌恶嗅觉调节过程中，厌恶冲击信息需要传递到MB，以便与气味信息联系起来。
附：英文原文
Title: Glia transmit negative valence information during aversive learning in Drosophila
Author: Tomoyuki Miyashita, Kanako Murakami, Emi Kikuchi, Kyouko Ofusa, Kyohei Mikami, Kentaro Endo, Takaaki Miyaji, Sawako Moriyama, Kotaro Konno, Hinako Muratani, Yoshinori Moriyama, Masahiko Watanabe, Junjiro Horiuchi, Minoru Saitoe
Issue&Volume: 2023-12-15
Abstract: During Drosophila aversive olfactory conditioning, aversive shock information needs to be transmitted to the mushroom bodies (MBs) to associate with odor information. We report that aversive information is transmitted by ensheathing glia (EG) that surround the MBs. Shock induces vesicular exocytosis of glutamate from EG. Blocking exocytosis impairs aversive learning, whereas activation of EG can replace aversive stimuli during conditioning. Glutamate released from EG binds to N-methyl-d-aspartate receptors in the MBs, but because of Mg2+ block, Ca2+ influx occurs only when flies are simultaneously exposed to an odor. Vesicular exocytosis from EG also induces shock-associated dopamine release, which plays a role in preventing formation of inappropriate associations. These results demonstrate that vesicular glutamate released from EG transmits negative valence information required for associative learning.
DOI: adf7429
Source: https://www.science.org/doi/10.1126/science.adf7429