Event:

Up to know the essential process resulting in the development of neurodegenerative diseases is not identified. In addition to many other risk factors, inflammatory incidents in the central nervous system (CNS) sustained early in lifetime are suspected to play an important role in the onset and progression of neurodegenerative processes. The CNS is vulnerable to different inflammatory occasions: Peripheral infections caused by various pathogens provoke inflammatory responses in the periphery but also in the immune privileged CNS. Other pathogens are able to enter the CNS and result in acute and chronic brain infections. To gain insight into cellular mechanisms and consequences of CNS infection and inflammation we stimulated inflammatory responses in the brains of mice using peripheral and cerebral infectants (influenza virus, LPS injections, and Toxoplasma infection in mice) and analyzed long-term effects on the structure and function of neurons, and also the activation of microglia cells. We focused especially on the hippocampus, a brain region responsible for processes of learning and memory. Our data provide evidence that peripheral and cerebral immune challenges result in long-lasting changes in neuronal morphology and function which might promote neurodegenerative processes. Furthermore, we observed that the IFNAR-signaling system might play a role in maintaining normal cognitive function under non-infectious conditions, showing how closely related neuronal and immunological signaling pathways can interact with each other.