t cell is the type of cell that contributes to the blood-brain barrier in the central nervous system.
t cell is the type of cell that contributes to the blood-brain barrier in the central nervous system.
what type of cell contributes to the blood-brain barrier in the central nervous system?
t cell
multiple sclerosis (ms) is considered to be an auto-immune and neurodegenerative disorder in which the immune system attacks the myelin that protects and electrically insulates the neurons of the central and peripheral nervous systems. normally, a person's nervous system would be inaccessible to the white blood cells due to the blood–brain barrier. however, magnetic resonance imaging has shown that when a person is undergoing an ms "attack," the blood–brain barrier has broken down in a section of the brain or spinal cord, allowing white blood cells called t lymphocytes to cross over and attack the myelin. it has sometimes been suggested that, rather than being a disease of the immune system, ms is a disease of the blood–brain barrier. the weakening of the blood–brain barrier may be a result of a disturbance in the endothelial cells on the inside of the blood vessel, due to which the production of the protein p-glycoprotein is not working well.
blood–brain barrier
in the brain, serotonin is a neurotransmitter and regulates arousal, behavior, sleep, and mood, among other things. during prolonged exercise where central nervous system fatigue is present, serotonin levels in the brain are higher than normal physiological conditions; these higher levels can increase perceptions of effort and peripheral muscle fatigue. the increased synthesis of brain serotonin occurs because of a higher level of tryptophan, the serotonin precursor, in the blood and which results in larger amounts of tryptophan crossing the blood-brain barrier. an important factor of serotonin synthesis is the transport mechanism of tryptophan across the blood-brain barrier. the transport mechanism for tryptophan is shared with the branched chain amino acids (bcaas), leucine, isoleucine, and valine. during extended exercise, bcaas are consumed for skeletal muscle contraction, allowing for greater transport of tryptophan across the blood-brain barrier. none of the components of the serotonin synthesis reaction are saturated under normal physiological conditions, allowing for the increased production of the neurotransmitter. however the failure of bcaas to decrease time to fatigue consistently limit this hypothesis.
central nervous system fatigue