In vitro odor-aversion conditioning in a terrestrial mollusk
In vitro odor-aversion conditioning in a terrestrial mollusk
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DOI：
10.1152/jn.00853.2005
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发表时间：
2006-06-01
影响因子：
2.5
通讯作者：
Kirino, Yutaka
中科院分区：
文献类型：
--
作者：
Inoue, Tsuyoshi;Murakami, Masayoshi;Kirino, Yutaka
我们在陆生软体动物Limax中开发了一个体外气味厌恶调节系统，并发现了嗅觉中枢神经系统网络振荡的行为相关性。我们首先研究了气味诱导的行为Limax，在气味厌恶条件反射在体内。缩短的外套膜肌肉，特别是观察到厌恶条件的气味。我们以前发现，顶叶神经，其中项目的外套肌肉在利马斯，调节外套肌肉缩短。因此，我们分离出整个大脑含有鼻子（感觉器官）和顶叶神经（运动输出），并施加了一个气味厌恶条件反射的范例，这些在体外制剂。在体外调理之前，将有吸引力的气味施加到鼻子上不会引起顶叶神经的任何放电。然而，在气味厌恶条件反射后，观察到顶神经的放电响应于天然的吸引力，但厌恶条件反射的气味。我们还发现，在procerebrum（PC），嗅觉中枢神经系统的Limax，网络振荡频率增加，特别是在反应的厌恶条件的气味，引起回避行为。在幼稚（非条件）的准备，PC振荡频率的增加，观察到特别是在响应先天厌恶的气味。这些结果表明，离体脑具有气味学习能力。他们还表明，PC网络振荡的变化与厌恶性条件反射和先天厌恶性气味有关，这两者都会引起回避行为。这种离体条件反射系统将是探索气味厌恶神经机制的有效途径。
We developed an in vitro odor-aversion conditioning system in the terrestrial mollusk, Limax, and found a behavioral correlate of network oscillation in the olfactory CNS. We first examined the odor-induced behavior of Limax, after odor-aversion conditioning in vivo. Shortening of mantle muscles was specifically observed in response to aversively conditioned odors. We previously identified that parietal nerves, which project to the mantle muscle in Limax, regulate shortening of the mantle muscle. We therefore isolated whole brains containing noses (sensory organs) and parietal nerves (motor output), and applied an odor-aversion conditioning paradigm to these in vitro preparations. Before the in vitro conditioning, application of attractive odors to the noses did not elicit any discharge in the parietal nerves. However, after odor-aversion conditioning, discharges in the parietal nerves were observed in response to the natively attractive but aversively conditioned odors. We also found that network oscillation frequency in the procerebrum (PC), the olfactory CNS of Limax, increased specifically in response to the aversively conditioned odors that elicited avoidance behavior. In naive (nonconditioned) preparations, increases in the PC oscillation frequency were observed specifically in response to innately aversive odors. These results indicate that the isolated brains have an ability of odor learning. They also suggest that changes in PC network oscillation are associated with aversively conditioned and innately aversive odors, both of which elicit avoidance behavior. This in vitro conditioning system would be an effective approach for exploring the neural mechanism to determine the aversion to odors.