Abstract

Bacterial meningitis is known to cause neurodegenerations in the hippocampus, a region of the brain concerned with learning and memory. Aim of the present study was to investigate the effect of pneumococcal meningitis on motor cortex and cerebellum in rats. 30 days old rats were divided into normal control (NC) and meningitis (M) groups. Rats in the meningitis group were infected with Streptococcus pneumonia intracisternally on postnatal day 31. The concentration of the bacterial suspension in phosphate-buffered saline (PBS) was 1 × 106 cfu/ml (colony forming units/ml). The rats were kept on observation for 18 h for clinical symptoms of meningitis to develop. After 18 to 24 h of incubation, 10 to 50 µl of the cerebrospinal fluid (CSF) sample was collected. Grams staining of the CSF smear was done and observed under oil immersion objective (100×) for Gram positive, lanceolate diplococci. The rats were perfused transcardially with saline followed by 10% formalin. Brain was removed, processed for paraffin sectioning, and stained with cresyl violet stain. The motor cortex and cerebellum showed neurodegeneration. Significant fractions of neurons in the motor cortex were darkly stained and a number of healthy neurons per unit area were decreased significantly. The purkinje cells were shrunken and their number was decreased significantly. Meningitis not only affected the hippocampus, but also other regions of the brain. Neurodegenerative changes were comparable to that observed in the hippocampus.

Key words: Meningitis, motor cortex, cerebellum, purkinje cells, neurodegeneration.