Neuronal basis of visually-guided insect behaviour and effects of neonicotinoid pesticides

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Animal survival depends on the nervous system's ability to collect and process relevant information and generate appropriate behavioural responses. Animals may be further challenged by presence of environmental toxicants (e.g. pesticides), that specifically target activity in the nervous system, and even low doses may have profound effects on neuronal processing and behaviour. Understanding the neural control of behaviour requires studying orientation in three-dimensional space and how kinematics of underlying locomotory appendages are driven by relevant muscle activity, followed by experiments on how the nervous system detects environmental cues and drives locomotory circuits. Combined activity of groups of neurons is crucial for detecting and deciphering complex sensory cues in animals ranging from humans to insects. Identifying mechanisms by which groups of neurons detect relevant cues from complex stimuli will also help us to understand mechanisms of potential behavioural impairment from pesticide exposure. The basic biological information can also enhance the design of biologically-inspired artificial systems capable of adaptable, self-guided navigation. My laboratory uses insect flight as an accessible system to address fundamental questions linking neurobiology and behaviour. We use techniques that include combinations of: 1) high speed video to track body and wing movements during flight, 2) electrical recordings of muscles that drive the wings, 3) single, multichannel and intracellular neurophysiological recordings of single or multiple neurons involved in visual processing, 4) effects of exposure to neonicotinoid pesticides on visually-guided behaviour, and 5) a virtual-reality environment with computer modelling to emulate real visual motion. We study responses of identified neurons in the locust nervous system to behaviourally-relevant visual cues. We are interested in how visual cues are processed and used to produce flight steering manoeuvres. Flight is complex, requiring rapid detection and processing of complex sensory signals and is controlled by relatively few neurons, making it accessible to rigorous experimental manipulation. For example, we examine how identified visual neurons respond to multiple objects or objects that change motion trajectory, which may or may not represent a danger to the animal. The three short-term objectives in this proposal include: 1) Understanding how multiple neurons code visual information and guide behaviour, 2) How pesticides disrupt neural processing and impair ecologically important behaviours in locusts and bees, and 3) Modelling neural and behaviour data to design algorithms for use in computational models and autonomous robots. Our work will be important for understanding fundamental processes of the neural control of behaviour and how these processes are affected by external stressors, and can also inform control strategies for artificial systems that orient in challenging environments.