Traditionally the central nervous system (CNS) has been thought to be ‘immune privileged’ and not interact with the immune system. Increasing evidence however suggests that many neurodegenerative diseases, as well as many acute injuries in the CNS, are characterized by the presence of inflammatory cells in the CNS. An initial response to neuronal injury is evidenced by the activation of CNS microglia.  Microglia are antigen-presenting, immune-competent, macrophage-like cells that reside in the CNS and are able to modulate neuronal survival, or are hypothesized to affect neuronal structural changes occurring in response to neuronal activity. Our research interests concern the communication, signaling events and cell-cell interactions between neurons and microglia subsequent to normal or exaggerated stimulation of the CNS that lead to reorganization of neuronal connections in the brain or neuronal cell death.