Functional assignment of projection interneurons of antennal lobe involved in neural processing of humidity and temperature information in insect brain.

我们对蟑螂大蠊和蜜蜂下脑触角叶的湿热信息处理进行了研究，揭示了触角叶中参与湿热信息神经处理的部分中间神经元的功能和形态特征。在这项研究中，我们已经确定了肾小球，其中轴突的水或热受体终止。感受器轴突用钴离子染色，其中一个包含两个湿受体，一个冷受体和另一个细胞，另一个包含一个冷受体和几个嗅觉受体细胞。湿热感受器受体细胞的一个轴突和热感受器和嗅觉感受器受体细胞的一个轴突终止于靠近背叶的肾小球丛。湿热感受器受体的两个轴突也终止于同一区域的另一组肾小球。这些团簇中的每一个似乎都来自一个类似于雄蛾的大肾小球复合体的肾小球复合体。另一方面，对湿热刺激反应强烈的投射神经元在这些肾小球簇中有树突，但对这些刺激反应弱的投射神经元似乎在其他肾小球中终止。因此，湿度和温度信息似乎主要分别通过这些肾小球簇传递给特定的投射中间神经元。

We have already investigated the hygro-and thermal information processing in the antennal lobe within the deutocerebrum of cockroach Periplaneta and honeybee Apis, showing that the functional and morphological characteristics of some interneurons in the antennal lobe which are involved in neural processing of hygro-and thermal information. In this study we have identified the glomeruli where the axons of the hygro-or thermo-receptors terminated. The receptor axons were ionophoritically stained by cobalt from the sensilla, one of which contained two hygroreceptors, one cold receptor and the other cell and the other contained one cold receptor and a few olfactory receptor cells. An axon of the receptor cell in the hygro-and thermoreceptive sensillum and an axon of the receptor cell in the thermoreceptive and olfactory sensillum terminate in a cluster of glomeruli which located near a dorsal lobe. Two axons of the receptors in the hygro-and thermoreceptive sensilla also terminated in another cluster of glomeruli in the same region. Each of these clusters appear to from a complex of glomeruli similar to the macroglomerular complex of male moths. On the other hand, the projection neurons that respond strongly to hygro-or thermal stimulations have dendritic arborizations in these glomerular clusters but the projection neurons show weak responses to these stimulations appear to terminate in other glomeruli. Therefore, humidity and temperature information appears to be primarily transmitted to the particular projection interneurons through these glomerular clusters, respectively.