| Abstract Eusocial insect colonies are tractable systems for analyzing how individuals coordinate to generate group behavior. The properties of the nervous system that influence worker behavior are poorly understood, but the mushroom bodies (MB) have received increasing attention because of their putative roles in sensory integration, learning and memory. Eusocial insects have relatively larger MB, particularly MB calyces, than related solitary species. This pattern implies that the MB calyces play an important role in regulating division of labor. Research in honey bees (Apis mellifera) supports this hypothesis by linking plasticity of the mushroom bodies with division of labor among workers. This suggests that the mushroom bodies may be important for adaptations to a changing environment or for adaptations to variations in individual tasks Honey bee foragers have larger Kenyon cell dendritic arbors, and increased calyces volume relative to the Kenyon cell body region, than do nurse bees. This difference is more strongly related to individual differences in task performance than to absolute age. These studies implicate the MB in the regulation of worker division of labor. Patterns of division of labor in Polyrhachis vicina Roger are convergent on those of honey bees, but whether similar MB changes are associated with task performance in Polyrhachis vicina Roger is not known. Passage through this task sequence is associated with neuroanatomical changes in the mushroom bodies (MB) of honey bee(Apis) workers. We asked whether Polyrhachis vicina Roger workers exhibit similar changes in adult neuroanatomy. Polyrhachis vicina Roger were identified as working in-nest, or foraging.. The purpose of the present investigation was to test the generality of MB structure/task associations in advanced eusocial Polyrhachis vicina Roger We asked whether MB anatomy corresponds to task performance in Polyrhachis vicina Roger Like honey bees, Polyrhachis vicina Roger workers exhibit strong task specialization. Polyrhachis vicina Roger are therefore a good system in which to test the generality of the brain/behavior relationships documented in ApisThe brain structure of Polyrhachis vicina Roger was observed by Nissl dyeing. The results indicated that the brain structure were composed of anterior, middle and hindbrain. A gigantic mushroom body in anterior showed that the ant has transcendent capability in learning and memory. There is big olfactory nerve fiber globe in middlebrain, which indicated that Polyrhachis Vicina Roger has well developed olfactory system. However, the optic globe was samller compared with other hymenoptera in anteriorbrain. So the optic system's function in looking for food, learning, memory and other behavior is inferior to olfactory globe. The hindbrain is very small, and it s function is not clear.Microscopic images were video-recorded and digitally stored in the Leica microscope and evaluated by a computer equipped with a video software of 3D-doctor and appropriate software adapted for volume measurements. From each microscopic section, the regions of calyces were traced on the computer screen and the surface calculated the mushroom body subcompartments of calyces. On the basis of the section thickness, the volume of the respective calyces was then calculated, the data of analysis indicate that the volume of two groups' calyces exist obvious difference.We subsequently analyzed the influence of foraging activity in greater detail, because foragers experience a greater variety of visual, olfactory and tactile stimuli in the foraging arenas and exhibit more motor activity. It is thus not surprising that in this study we found the larger volume changes in the calyces, which are the structures most closely connected with the adaptability and behavioural complexity of the ant. Striking morphological difference between foragers and nurses. May behave differently and may live in different sensory environments (e.g. foragers worked outside looking for foods and transporting material while nurses live permanently in the dark nest Cultivating fungus), within a colony they are sisters and genetically very similar. Ants offer a unique opportunity to assess the effects of a wide range of behavioural and morphological differences without the problems arising from genetic variability when comparing different species. For these reasons, we think that much can be learned about neuronal plasticity and the adaptation of the nervous system by studying the brain of Polyrhachis vicina Roger... |
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