Fig. 4

Learning and memory performance 3 weeks after acute pneumococcal meningitis assessed by Morris water maze. (a) Schematic representation of our Morris water maze protocol used during these experiments (scheme sketch inspired by Kipnis et al. [35]). Learning performance assessed on five consecutive days revealed impaired learning of infected animals compared to mock-infected animals. Infected animals treated with combined adjuvant therapy revealed significantly improved learning behaviour compared to their infected counterparts receiving CRO monotherapy (b). Memory assessment—by analysing the first training trial for each day separately—showed significantly reduced memory performance in infected animals compared to mock-infected animals. Infected animals treated with combined adjuvant therapy showed significantly improved memory compared to their infected counterparts treated with CRO monotherapy (c). Memory formation assessed with probe trials after removing the platform further demonstrated the impaired performance of infected animals with CRO monotherapy to infected animals receiving combined adjuvant therapy and to mock-infected animals (d). Statistical differences were assessed by two-way ANOVAs to compare learning and memory performance between groups over repeated time points