Immune reactions in the central nervous system (CNS) – the brain and spinal cord – differ from other organs. Under normal conditions, the endothelial cells lining blood vessels in the brain act as a “blood-brain barrier” to block the entry of most immune cells into the CNS. In some CNS diseases like multiple sclerosis, and in trauma, stroke and infections, this barrier is compromised. As a result, immune cells migrate to the brain in large numbers causing inflammation, which can lead to serious consequences. Azadeh Arjmandi is studying how immune cells gain access to the brain and spinal cord in infectious, inflammatory and autoimmune diseases. Immune cells called dendritic cells have been found in the central nervous systems of patients with these diseases and their numbers increase with more chronic conditions. Azadeh is examining dendritic cell trafficking across the blood-brain barrier in order to further characterize the molecular mechanisms of inflammation in the brain. This will provide important information about how certain CNS diseases develop and may contribute to more effective treatments.