Date Time Immune cells attack synapses Damage to the brain gray matter plays an important role in the progression of multiple sclerosis. A team of neuroscientists has now shown that the cause are inflammatory responses that lead to synapse loss, reducing neuronal activity. Targeted inhibition of these immune cells could mitigate such synaptic damage, and therefore provides a promising therapeutic option for progressive multiple sclerosis. Multiple sclerosis (MS) is a chronic inflammatory disease that affects the central nervous system, in which nerve cells are attacked by the patient’s own immune system. In many cases, the disease develops into a progressive form, which is characterized by a shift of pathology from the white matter to the gray matter, for instance to the cerebral cortex. This phase of the disease has so far been difficult to treat and its underlying causes are poorly understood.