Figure 1.

Infection differentially affects BDNF protein isoforms in aged versus young animals. Western blot analysis showing enrichment of synaptic material in synaptoneurosomes, and levels of proBDNF and mature BDNF in hippocampal synaptoneurosomes prepared from young and aged rats, with and without a recent history of infection. A, Representative examples of blots probed with a PSD95 antibody to confirm enrichment of synaptic material in the synaptoneurosomal (P2) versus the cytosolic (S2) fractions. B, Levels of proBDNF were not significantly reduced by the combination of aging and infection. C, Infection markedly reduced mature BDNF in synaptic fractions from aged animals. Band intensities were quantified (ImageJ), normalized to actin controls, and expressed as percentages of mean protein levels from young vehicle-injected rats. Error bars indicate SEM. All graphs (here and below) represent a minimum of three independent experiments with one to two animals per group in each experiment. Asterisks indicate statistical significance from all other groups; individual p values are reported in the text.