Whole genome microarray gene expression profiling of hippocampal genes from aged rats subjected to chronic unpredictable mild stress

Psychological, psychosocial and physical stress are major risk factors, which enhance the development of sporadic late-onset Alzheimer`s disease. The chronic unpredictable mild stress model mimics those risk factors and triggers signs of neurodegeneration and neuropathological features of sporadic AD such as tau hyperphosphorylation and enhanced amyloid beta generation. The study investigated the impact of chronic unpredictable mild stress on signs of neurodegeneration by analyzing hippocampal gene expression with whole genome microarray gene expression profiling. Whole genome microarray gene expression profiling was performed to study the impact of stress on hippocampal gene expression. Aged male rats (15 months of age) were subjected to the chronic unpredictable mild stress (CUMS) battery for four weeks. Thereafter at an age of 16 months, 4 h before the beginning of the dark phase, rats were anesthetized, the hippocampus was dissected out on ice and processed for whole genome microarray gene expression profiling according to the protocol of the manufacturer (Affymetrix). The study used the GeneChip Rat Genome 230 2.0 Array for whole genome gene expression analysis of hippocampal genes from stressed rats relative to age-matched non-stressed controls.Two biological replicates were made of each group, and total hippocampal RNA of three rats was pooled for one gene chip.