Methods An infant rat model of experimental pneumococcal meningitis was used. Cortex and hippocampus were dissected from animals in acute and late disease i.e. at 24 and 72 hours after infection. Gene expression profiles were assessed with Affymetrix GeneChip® Rat 230 2.0 arrays. Involved biological processes were identified by grouping gene with altered expression, using GO (Gene Ontology)based statistics. Cell proliferation in the dentate gyrus was also investigated using BrdU incorporation. Infected animals and uninfected control littermates received BrdU for 3 consecutive days at different times after infection. Density of BrdU positive cells was determined by immunofluorescence.