An Initial Attempt to Correlate Prefrontal Cortex mRNA Transcripts with Behavioural Variation in Lewis Rats

Despite virtually identical genomes, inbred animals often vary in phenotype, including behaviour, but the molecular basis of this phenomenon is unknown. Our hypothesis is that differences in behaviour between inbred rats are correlated with differential cortical mRNA transcript levels. 40 Lewis rats were subjected to 5 behavioural tests: two were used to categorize 10 animals into either “high” or “low” phenotype groups. Microarray gene expression profiling was performed for 5 rats from each group. Three main analyses were performed to: (1) identify differential expression between the high and low groups, (2) identify correlations between transcript levels and individual behaviour scores, and (3) determine if the results of this replicate experiment overlapped with a previous pilot experiment. Some array results were confirmed by RT-PCR. We found that this experiment did not replicate the findings from the pilot, however several genes of interest were determined and were validated by RT-PCR.MAS