The researchers link this to the daily fluctuations in the activity of neutrophils.
Scientists at the National Research Center Carlos III in Spain have concluded that the severity of the consequences of ischemic stroke depends on the time of day when the pathological process develops. According to the results of the study, during the dark hours, damage to brain tissue is generally more profound and extensive. This is reported by CirRes.
The researchers link this to the daily fluctuations in the activity of neutrophils — cells of innate immune defense that are the first to respond to ischemic injury. In experiments on animals, as well as in the analysis of clinical data from over 500 patients, it was established that at certain stages of the circadian rhythm, neutrophils enter a state of increased inflammatory activity.
During the evening and nighttime hours, these cells intensively form so-called extracellular traps — complexes of DNA and protein molecules. Normally, such structures participate in the fight against infectious agents; however, during a stroke, their excessive amount disrupts blood supply to the brain. As a result, the formation of microthrombi is intensified, which slows down the recovery processes.
In the morning period, neutrophils, on the contrary, demonstrate a more restrained response, which limits the extent of damage during a stroke. These data help to understand why patients with outwardly similar symptoms may experience the disease differently.
