Memory lapses: opportunities for adaptive behaviour

点击翻译按钮获取中文摘要

Associative conditioning is one of the most basic means by which animals learn to exploit the predictive value of particular sensations in a complex sensory environment. It provides a fundamental mechanism underlying the ability to respond adaptively to sensory signals that are associated with for example opportunity or threat. For instance, certain olfactory sensations may presage the presence of food. By learning such an association, an animal can more effectively locate and exploit food resources. Some sensations may become associated with threat, in which case the learned adaptive response might be withdrawal. Following the initial formation of an associative memory there is a period of consolidation, during which the conditioned behaviour becomes progressively more permanent. Recently however, we found that during consolidation there are brief periods of amnesia during which the progression to long-term storage can be blocked by unanticipated changes in the sensory environment. The time-points of memory lapses and susceptibility correspond to transitions in the dependency on different underlying molecular and cellular mechanisms as consolidation proceeds. Our discovery of the susceptibility of memory formation to interference suggests that associative conditioning is a far more flexible process than hitherto appreciated. The overarching aim of this proposal is to advance our understanding of the fundamental mechanisms underlying behavioural flexibility during the critical consolidation period. We will exploit the advantages offered by the relatively simple brain and behaviour of the mollusc Lymnaea. While having a CNS of only 20,000 neurons, this animal nevertheless shares all of the basic features of associative memory formation displayed by far more complex animals, including humans. This allows us to study a universal form of behavioural adaptation and flexibility at a level of cellular and molecular detail that would not be possible in more complex animals. Because we know that the process of memory formation and its underlying cellular and molecular mechanisms are evolutionarily highly conserved, this research is likely to reveal principles and mechanisms of behavioural flexibility that apply equally to both simple and complex animals. In the longer term this research may lead to the discovery of new drugs or procedures that can modify the flexibility of memory formation with the potential benefit that this may have for the treatment of memory disorders.