Contaminant effects on chemical communication in aquatic animals: targeted effects and recovery during continuous exposure conditions

我研究的长期目标是了解污染物引起的水生动物化学通讯系统损伤的原因和后果。这些动物利用气味来躲避捕食者、寻找食物或繁殖。信息分子以氨基酸（食物和迁徙线索）、信息素（性线索）或胆汁酸（捕食线索）的形式被嗅觉系统感知，并引发刻板的行为反应。环境污染会干扰嗅觉，导致一种不适应状况：“信息中断”。众所周知，在实验室和野外条件下，污染物引起的信息中断会影响许多暴露于环境相关污染物浓度的物种。嗅觉感觉神经元（OSNs）有三个亚群：纤毛细胞、微绒毛细胞和隐窝细胞，它们分别对胆汁酸、氨基酸或信息素敏感。不同的osn -亚型使用不同的分子机制，使我们能够区分哪种osn -亚型负责处理特定的气味。我们已经确定金属靶向OSN亚型，影响特定行为。在野生种群中，鱼对特定气味的敏感性可能受到生态环境的影响。例如，当食物匮乏时，由于微绒毛osn增加，鱼类可能对食物线索过敏。相反，在被以纤毛osn为目标的物质污染的环境中，鱼类可能无法发现和躲避捕食者。本研究的目的是：(i)建立特定osn亚型功能障碍与鱼类行为影响之间的关系，（ii）确定生态环境或生理状态是否可以补偿污染物对嗅觉的影响，（iii）确定鱼类或无脊椎动物在持续暴露期间是否会恢复，如果是，确定恢复机制（iv）确定自然种群是否适应或补偿污染物引起的化学感觉缺陷。实验方法是在控制和野外条件下研究实验室饲养的和野生的鱼类和水生无脊椎动物。化学感觉功能将使用完善的行为和神经生理学技术（即，电嗅图；EOG）进行测量。药理学试剂将用于确定OSN参与检测特定线索。这项工作的意义在于了解化学通讯系统在水生生态系统中的重要作用，以及生活在被极低浓度金属污染的环境中的水生动物种群的相关风险。由于化学通讯系统调节与生存、生长和繁殖相关的行为，信息中断可能导致适应不良的影响，从而对整个生态系统产生重要影响。

The long-term objective of my research is to understand the causes and consequences of contaminant-induced impairment of chemical communication systems among aquatic animals. These animals use smells to avoid predation, find food, or reproduce. Infomolecules, in the form of amino acids (food and migratory cues), pheromones (sex cues), or bile acids (predator cues), are perceived by the olfactory system and trigger stereotypical behavioural responses. Environmental contamination can interfere with olfaction leading to a maladaptive condition: 'infodisruption.' Contaminant-induced infodisruption is known to affect many species exposed to environmentally-relevant contaminant concentrations under lab and field conditions. Three subpopulations of olfactory sensory neurons (OSNs) occur in fish: ciliated, microvillous, and crypt cells that are sensitive to bile acids, amino acids, or pheromones, respectively. Different molecular mechanisms are used by different OSN-subtypes, allowing us to differentiate which OSN-subtype is responsible for processing specific odours. We have established that metals target OSN subtypes which affect specific behaviours. In wild populations, a fish's sensitivity to a particular smell may be affected by ecological context. For example, fish may be hypersensitive to food cues when food is scarce because of increased microvillous OSNs. Conversely, fish in environments contaminated by substances that target ciliated OSNs may not be able to detect and avoid predators. The objectives of this research are: (i) To establish the relationship between specific OSN-subtype dysfunction and behavioural effects in fish, (ii) to determine if ecological context or physiological state can compensate for contaminant effects on olfaction, (iii) to determine if recovery in fish or invertebrates occurs during continuous exposure, and if so, to determine the mechanism of recovery (iv) to determine if natural populations adapt or compensate for contaminant-induced chemosensory deficits. The experimental approach is to study both lab-reared and wild fish and aquatic invertebrates under controlled and field conditions. Chemosensory function will be measured using well-established behavioural and neurophysiological techniques (i.e., electro-olfactography; EOG). Pharmacological agents will be used to determine OSN involvement in the detection of specific cues. The significance of this work lies in understanding the vital role of chemical communication systems in aquatic ecosystems, and the associated risk to aquatic animal populations inhabiting environments contaminated with even very low concentrations of metals. Because chemical communication systems mediate behaviours associated with survival, growth, and reproduction, info-disruption can lead to maladaptive effects that can have important ramifications to the entire ecosystem.