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

我们已经研究了蟑螂大小蜂和蜜蜂的中脑内触角叶的湿热信息处理，结果表明，触角叶中一些参与湿热信息神经处理的中间神经元的功能和形态特征。在这项研究中，我们已经确定了水温感受器轴突终止的肾小球。感受器轴突被来自感受器的钴离子染色，其中一个感受器含有两个湿感受器，一个冷感受器和一个细胞，另一个感受器含有一个冷感受器和少数嗅觉感受器细胞。感湿感受器和嗅觉感受器的感受器细胞的轴突和感温感受器和嗅觉感受器的感受器细胞的轴突终止于位于背叶附近的一簇肾小球。感湿性和感热性感受器中的两个轴突也终止于同一区域的另一簇肾小球。这些簇中的每一个似乎都形成了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，对水或热刺激反应强烈的投射神经元在这些肾小球簇内有树突分支，但对这些刺激反应较弱的投射神经元似乎终止于其他肾小球。因此，湿度和温度信息似乎主要通过这些肾小球簇传递到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.