Behavioural Physiological and Molecular Mechanisms of Phase Change in Locusts

蝗虫相变的行为生理和分子机制

• 批准号: BB/D018587/1
• 负责人: Thomas Matheson
• 金额: $ 33.23万
• 依托单位: University of Leicester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FD018587%2F1
• 关键词: Behavioural; Physiological; Molecular; Mechanisms; Phase

Many animals undergo profound changes in form and function in response to fluctuating environmental conditions, of which the Desert Locust is a notorious example. It can change reversibly from a cryptic solitary living form to a swarming form that occasionally aggregates in vast numbers to devastating effect. These two forms, the solitarious and gregarious phases, differ considerably in appearance, physiology and behaviour. Since a major goal of Neuroscience is to understand how changes in behaviour are underpinned by modifications of the nervous system, phase change in locusts is a powerful model system in which to pursue this goal. Our aims in this research proposal are three-fold. The first is to understand how signals provided by other locusts act on the central nervous system of solitarious locusts and start to modify the connections between nerve cells so that a previously solitarious locust will behave like a gregarious locust within 4 hours of first contact. We already know that touch signals provided by other locusts drive behavioural gregarization and that these signals trigger the release of two substances in the central nervous system. We wish to know how touch stimuli cause these substances, serotonin and nitric oxide, to be released, which nerve cells they are released from and on which target nerve cells they act. Most importantly, what biochemical reactions do they trigger in these target cells to so profoundly change the locust's behaviour? To find out we will study the changes in brain chemistry that occur as locusts change phase. Can drugs that prevent these changes also prevent a locust from turning gregarious? We also need to ask whether such biochemical processes suffice to switch the behaviour or whether it is necessary to switch genes on or off. Our second aim is to understand how differences in the properties of nerves cells and the connections between them lead to altered behaviours in solitarious and gregarious locusts. To do this we will exploit the fact that insects have many large and identifiable neurons that can be recorded from in many individuals. We have focussed on an identified visual nerve cell that responds to objects on collision course with the locust. We will analyse the connections of this cell to motor nerve cells that control the wings and hind leg and determine whether they are modified in the same way during phase change or if they are independently adjusted to suit particular behaviours. Are the strengths of connections made by another nerve cell that detects wing movements modified in a similar way as the visual nerve cell? Gregarious locusts fly by day and solitarious locusts mostly at night. We wish to know how the responses of the visual system are adjusted to the day- and night-time activities of the two phases and whether an internal clock in the central nervous system changes the sensitivity of the eyes and visual interneurones in anticipation of the onset of daylight or dusk. Our third aim is to analyse the ageing rate of solitarious and gregarious locusts and how this affects the function of nerve cells. Solitarious locusts live 45% longer as adults than gregarious allowing us to manipulate the rate of ageing of locusts by changing their phase. Living cells accumulate the breakdown products of ageing-related damage, called lipofuscin, into granules that can be seen under a microscope allowing us to measure the rate of ageing in individual nerve cells. Furthermore, nitric oxide, one of the substances that are produced in abundance during phase change causes ageing-type damage to cells. We will determine whether the process of phase-change itself causes accelerated ageing over and above that expected from a locust already being in a gregarious phase. We will record from the same identified motor nerve cells detailed above to analyse how ageing changes the way in which a nerve cell responds to incoming signals and communicates with other nerve cells.

许多动物在形态和功能上都经历了深刻的变化，以应对不断变化的环境条件，沙漠蝗虫就是一个臭名昭著的例子。它可以可逆地从一个神秘的孤独的生活形式转变为一个群集的形式，偶尔聚集在大量的破坏性影响。这两种形式，独居和群居阶段，在外观，生理和行为上有很大的不同。由于神经科学的一个主要目标是了解行为的变化是如何通过神经系统的修改来支撑的，蝗虫的相变是追求这一目标的强大模型系统。我们在这项研究计划中有三个目标。首先是了解其他蝗虫提供的信号如何作用于独居蝗虫的中枢神经系统，并开始修改神经细胞之间的连接，使以前独居的蝗虫在第一次接触后4小时内表现得像群居蝗虫。我们已经知道，其他蝗虫提供的触摸信号会驱动行为集群化，这些信号会触发中枢神经系统中两种物质的释放。我们希望知道触摸刺激如何导致这些物质，血清素和一氧化氮，释放，它们从哪些神经细胞释放，以及它们作用于哪些目标神经细胞。最重要的是，它们在这些靶细胞中引发了什么生化反应，从而如此深刻地改变了蝗虫的行为？为了找到答案，我们将研究蝗虫改变相位时大脑化学物质的变化。阻止这些变化的药物是否也能阻止蝗虫变成群居动物？我们还需要问这样的生化过程是否足以改变行为，或者是否有必要打开或关闭基因。我们的第二个目标是了解神经细胞特性的差异以及它们之间的联系如何导致孤独和群居蝗虫行为的改变。为了做到这一点，我们将利用昆虫有许多大的和可识别的神经元，可以从许多个体中记录下来的事实。我们已经集中在一个确定的视觉神经细胞，响应对象的碰撞过程中与蝗虫。我们将分析这种细胞与控制翅膀和后腿的运动神经细胞的连接，并确定它们是否在相变期间以相同的方式进行修改，或者它们是否独立调整以适应特定的行为。另一个检测翅膀运动的神经细胞的连接强度是否与视觉神经细胞的连接强度相似？群居的蝗虫白天飞行，独居的蝗虫大多在晚上飞行。我们希望知道视觉系统的反应如何适应这两个阶段的白天和夜间活动，以及中枢神经系统中的内部时钟是否会改变眼睛和视觉中间神经元的敏感度，以预测黎明或黄昏的到来。我们的第三个目标是分析独居和群居蝗虫的衰老速度，以及这如何影响神经细胞的功能。独居的蝗虫比群居的蝗虫寿命长45%，这使得我们可以通过改变蝗虫的阶段来操纵它们的衰老速度。活细胞将衰老相关损伤的分解产物（称为脂褐素）积累成颗粒，这些颗粒可以在显微镜下看到，从而使我们能够测量单个神经细胞的衰老速度。此外，一氧化氮，在相变过程中大量产生的物质之一，会对细胞造成老化型损伤。我们将确定阶段变化过程本身是否会导致加速老化，超过已经处于群居阶段的蝗虫的预期。我们将从上面详细描述的相同的运动神经细胞中记录下来，以分析衰老如何改变神经细胞对传入信号的反应以及与其他神经细胞通信的方式。

项目成果

Rapid behavioural gregarization in the desert locust, Schistocerca gregaria entails synchronous changes in both activity and attraction to conspecifics.

• DOI: 10.1016/j.jinsphys.2014.04.004
• 发表时间: 2014-06
• 期刊: JOURNAL OF INSECT PHYSIOLOGY
• 影响因子: 2.2
• 作者: Rogers, Stephen M.;Cullen, Darron A.;Anstey, Michael L.;Burrows, Malcolm;Despland, Emma;Dodgson, Tim;Matheson, Tom;Ott, Swidbert R.;Stettin, Katja;Sword, Gregory A.;Simpson, Stephen J.
• 通讯作者: Simpson, Stephen J.

Microarray-based transcriptomic analysis of differences between long-term gregarious and solitarious desert locusts.

基于微阵列的转录组分析长期群居和独居沙漠蝗虫之间的差异。

• DOI: 10.1371/journal.pone.0028110
• 发表时间: 2011
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Badisco L;Ott SR;Rogers SM;Matheson T;Knapen D;Vergauwen L;Verlinden H;Marchal E;Sheehy MR;Burrows M;Vanden Broeck J
• 通讯作者: Vanden Broeck J

The Insects - Structure and Function

昆虫 - 结构和功能

• DOI: 10.1017/cbo9781139035460.030
• 发表时间: 2012
• 作者: Matheson T