Aurora Semerano, MD
Liu L, Kearns KN, Eli I, Sharifi KA, Soldozy S, Carlson EW, Scott KW, Sluzewski MF, Acton ST, Stauderman KA, et al. Microglial Calcium Waves During the Hyperacute Phase of Ischemic Stroke. Stroke. 2021;52:274–283.
Microglia are the main resident immune cell population of the central nervous system and play a key role in brain development, homeostasis and repair. During ischemic stroke, microglia are rapidly activated, and characterized by morphological, proliferative and functional alterations. The role of microglia activation in ischemic stroke remains highly controversial in the preclinical setting and depends on multiple factors, including the experimental conditions and the phase of the disease. More recently, an additional role for microglial cells has been proposed, since they have been found to be implied in the occurrence, the sensing and the response to cortical spreading depolarization (CSD).1 CSD is defined as a slowly propagating (2–5 mm/min) wave of rapid, near-complete depolarization of neurons and astrocytes followed by a period of electrical suppression of a distinct population of cortical neurons. CSD is considered as the biological substrate of migraine aura, but it has been shown to occur in other neurological conditions, such as ischemic stroke, subarachnoid hemorrhage and traumatic brain injury.2 In other words, CSD consists in a deep perturbation of the ionic environment in the brain, which has been associated with excitotoxicity damage and vaso-occlusive phenomenons after brain injury.