AbstractAssociative recognition memory enables judgements of whether configurations of stimuli have been previously encountered and these memories require de novo protein synthesis in the CA1 subregion of the hippocampus for their consolidation. To investigate associative recognition memory in the present study, the paired viewing procedure (Zhu et al, 1996) was used to present novel and familiar arrangements of images using a within-subjects design. A previous report of increased Fos expression in the novel compared to the familiar condition in CA1 following paired viewing of arrangements was replicated.
As there is increased sensitivity to subtle changes in gene expression in the translatome compared to the transcriptome, translating ribosome affinity purification (TRAP; Heiman et al, 2008) was used to extract messenger RNAs engaged with the ribosome by tagging the ribosomal protein L10a with EGFP. In this thesis, viral vectors expressing the EGFP-L10a transgene were developed to target CA1 pyramidal neurons.
Combining TRAP and paired viewing, a study profiling the translatome of rat CA1 neurons over time following paired viewing was conducted, aiming to further understanding of the genes and regulatory networks involved in associative recognition memory. As gene expression is also induced in response to behavioural conditions not requiring learning, a no-image control condition was included with matched timepoints. TRAP-generated RNA samples were sequenced and submitted to a range of bioinformatic analyses to identify genes that were differentially expressed between novel and familiar conditions and over time. There was strong evidence of enriched protein-protein interactions between differentially expressed genes (DEGs) and potential regulators of the DEG network were identified. This first translatome profiling study of associative recognition memory sheds light on the dynamics of gene expression during learning and identifies promising candidate genes and molecular functions of interest for follow-up studies.
|Date of Award||25 Sep 2018|
|Supervisor||James B Uney (Supervisor), Clea Warburton (Supervisor) & Lucia Marucci (Supervisor)|