Increased neuronal proliferation in human bacterial meningitis.

OBJECTIVE

Neurogenesis is increased in experimental models of bacterial meningitis. In this study, neurogenesis was examined after bacterial infection of the CNS, and after stroke and brain trauma in humans.

METHODS

Brain sections of patients after death from bacterial meningitis, stroke, or brain trauma and from autopsy cases after death from nonneurologic diseases were investigated by immunohistochemistry.

RESULTS

In the dentate gyrus, the density of proliferating cellular nuclear antigen-expressing cells was higher after bacterial meningitis compared to the control group (p = 0.0075). Furthermore, the number of cells expressing the immature neuronal marker proteins TUC-4 and doublecortin were increased in brain sections of patients after death from meningitis compared to control cases (p = 0.0067 and p = 0.045). After stroke and brain trauma, higher densities of proliferating cells were observed (p = 0.031 and p = 0.018), while an increase of TUC-4-expressing cells was detected after stroke only (p = 0.0012 and p = 0.47).

CONCLUSIONS

The increased proliferation of neural progenitors suggests an endogenous mechanism in response to noxious stimuli. Stimulation of neurogenesis might help to alleviate the consequences of neuronal destruction in bacterial meningitis and other diseases of the brain.