Mechanisms of short term habituation in C. elegans

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Although many researchers focus on the mechanisms of long-term memory, there are fewer researchers who focus on the mechanisms of short-term memory. The objectives of the research described in this proposal are to focus on discovering the mechanisms underlying short-term memory for a very simple form of learning, habituation in a very simple model system, the nematode C. elegans. Habituation involves learning to ignore stimuli that are repeated and that do not have any meaning (i.e. traffic sounds, the sound of a fan in the room, the movement of leaves on a tree). All animals can learn this. We will approach studying the mechanism of this type of learning at the level of behaviour, at the level of the neural circuit and at the level of genes. For the behavioural aspects of the proposed research we will try to break the behaviour down into its component parts in order to investigate which features in addition to interstimulu interval (stimulus frequency), response magnitude and response frequency of habituation are independently mediated. At the level of the neurons we will use tools to assess gene activation in identified neurons (ie. green fluorescent protein, Western blots, quantitative real time PCR, transgenic cell specific rescues of mutations) to focus on whether the mechanisms mediating different aspects of habituation are in the sensory neurons or the interneurons in origin. Finally at the level of the gene we will use a genetic screen to identify a large number of genes that play a role in habituation in C. elegans. In addition we will analyze classical conditioning in the mutants we identify to see whether genes that affect habituation also affect classical conditioning. In this way we will investigate the relationship between habituation and classical conditioning.