Neural mechanisms of memory reconsolidation

Exton-McGuinness, Marc Thomas James (2014). Neural mechanisms of memory reconsolidation. University of Birmingham. Ph.D.

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Abstract

This thesis investigates the mechanisms of memory reconsolidation, with a particular focus on instrumental memories. Memories are dynamic in nature and can destabilise and re-stabilise in order to strengthen and update with new information. Destabilisation renders memories labile and vulnerable to amnestic intervention, requiring a reconsolidation phase in order to return to a stable form. Reconsolidation has been demonstrated in a great many memory settings, however the memories underpinning instrumental behaviours have not yet been shown to undergo reconsolidation. Starting from the hypothesis that reconsolidation mediates memory updating, this thesis investigates the reconsolidation of instrumental memories using primarily lever pressing in rats as a model, but also a novel active avoidance paradigm; reconsolidation is also investigated in a place aversion setting. Instrumental memories are found to destabilise following a suitable change in contingency, and their reconsolidation is shown to require activity at the N-methyl-D-aspartate receptor (NMDAR), and in the case of goal-directed memory, co-activation of dopamine-1 and NMDARs. Consideration of the conditions under which instrumental memories will and will not destabilise suggests certain boundary conditions on reconsolidation and this thesis proposes that a change in incentive outcome is required in order for memories to be destabilised.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):