?? ???? ????? ?? ??? ?? ???? ??? ???? ????? ?????? ?? ??????? ?? ???? ?????? ??? ???? ?? ???? ????? ?? ?????? ???? ?????The endothelial cells in the cerebral blood vessel walls are joined tightly to one another, forming the blood–brain barrier, which blocks the passage of many toxins and pathogens[35] (though at the same time blocking antibodies