Notes

Microglia Microglia cells are involved in the "immune system" of the brain.

Three-Step Model of Microglial Phagocytosis Microglia need to react to different signals to find "disturbing" elements (e.g., apoptotic cells) and they do so by reacting to chemoattraction. Then, they receive signals to eat (phagocytose) these elements and digesting them.

Microglial Phagocytosis in Health Microglia are acting also when there is not necessary a lesion or something going "bad", but also during pruning. There is always microglial activity also when there is not some major problem going on.

Microglial Phagocytosis in Disease However, if there is something major going on, microglia play an important role in helping.

Cerebral Blood Vessels The brain is very densely vascularized, mainly because it has a very high energy consumption, which is associated with high oxygen requirements. Not all areas are equally vascularized. There exist three main types of vessels: arteriole, capillary and venule. It is important to notice that blood vessels don't allow the passage of any elements if not for gas diffusion (O2 and CO2) and those mediated by protein channels passages. Blood flow is often use to analyze the brain activity through fMRI as a non-invasive technique.