Spatial memory and learning deficits after experimental pneumococcal meningitis in mice.

Area of Science:

• Neuroscience
• Infectious Diseases
• Pathology

Background:

• Bacterial meningitis survivors often experience lasting neurological impairments, notably learning and memory deficits.
• Streptococcus pneumoniae is a common cause of bacterial meningitis with significant morbidity.

Purpose of the Study:

• To investigate long-term spatial learning and memory deficits in a mouse model of ceftriaxone-treated Streptococcus pneumoniae meningitis.
• To assess the persistence of cognitive impairments following bacterial meningitis.

Main Methods:

• A mouse model was established by introducing Streptococcus pneumoniae into the forebrain.
• Spatial learning and memory were evaluated using the Morris water maze test at different time points post-infection.
• Motor function was assessed to differentiate cognitive deficits from motor impairments.

Main Results:

• Mice surviving meningitis exhibited significant and persistent deficits in spatial learning and memory compared to control groups.
• These deficits were evident even 180 days after the initial infection, particularly when relearning a changed platform location.
• Motor function remained normal, indicating the observed impairments were specific to cognitive processes.

Conclusions:

• Ceftriaxone-treated Streptococcus pneumoniae meningitis leads to long-lasting spatial learning and memory deficits in mice.
• These findings highlight the potential for chronic cognitive impairment in bacterial meningitis survivors.
• The Morris water maze is a sensitive tool for detecting persistent spatial memory deficits after meningitis.