Researchers from the National Institute on Aging in Baltimore have produced an "atlas" of the activity of nearly 17,000 genes in 5 different regions of the mouse central nervous system.

Using microarrays, the NIA team measured the levels of mRNA transcripts in the cortex, hippocampus, striatum, cerebellum and spinal cord. Samples were taken from young, middle-aged and old-aged mice of both sexes, and maintained on either a normal or a calorie restricted diet.

In this way, the transcriptome of each region, or the whole repertoire of mRNAs found in each region, was obtained. The transcriptomes were compared, and the influence of age, diet and gender on each one was determined.

The figure above shows a gene cluster analysis of the hippocampus transcriptome. Each of the 6 rows represents a transcriptome obtained from mice maintained on a different calorie-restricted diet, and each of the small coloured bars within the rows represents a family of related transcripts.

Overall, it was found that less than 10% of the transcripts were significantly affected by age, diet or gender. The spinal cord was most affected by the three factors, and the striatum the least, with most changes in the transcriptome occuring between middle- and old-age. The hippocampus transcriptome was most affected by gender and diet, and synaptic vesicle trafficking proteins were among the groups of genes affected most by age and diet.

The study is published in the open access journal Genome Biology, and is available as a provisional PDF. Microarrays produce massive data sets, so further analysis of the results obtained here could provide researchers with more information.

Reference:

Xu, X., et al. (2007). Gene expression atlas of the mouse central nervous system: impact and interactions of age, energy intake and gender. Genome Biology 8: R234 doi:10.1186/gb-2007-8-11-r234. [PDF]