Why si BBB important? No matter what age you are?
1- The blood-brain barrier (BBB) mediates the communication between the periphery and the central nervous system (CNS). Recently, CNS insulin resistance has been elucidated to play a role in neurodegenerative disease. This has stimulated a wealth of information on the molecular impact of insulin in the brain, particularly in the improvement of cognition.
2- neurons
Neurons remain close to the capillaries and connect with astrocytic endfeet in near proximity to the BBB. Neurons are rarely more than 8–20 μm from a brain capillary,The close proximity to the endothelial cells, allows neurons to respond to the ever changing local milieu, especially in regards to ion balance. Neurons play a role in regulating blood flow.the neuronal circuitry is linked to the blood vessels by water channels present in astrocytes.
3- Astrocytes
Astrocytes are the most abundant cells in the brain, providing an environment to help regulate all aspects of neuronal function (survival, development, metabolism, neurotransmission). They act as metabolic sensors in the brain responding to changes in the local environment, At the BBB, astrocytes help provide maintenance and repair support through release of several effector molecules, The astrocytic endfeet ensheath the vascular tube and help to regulate ion and water regulation.
Using this system, the brain can regulate fluid flow throughout the CNS (Central Nervous System) and aid in clearance of toxins. In addition, the connection between neurons and blood vessels allows astrocytes to relay signals regarding blood flow, Astrocytic end feet are polarized and guided to cerebral vessel walls by pericytes.
4- Pericytes
Pericytes are essential for development of tight junctions, including in the development of barrier functions in utero.
Pericytes can regulate blood flow in response to neural activity, suggesting an important role in mediating vascular tone and highlighting the neural communication necessary for this particular function.
Interruptions in signaling within one cell type could have detrimental effects in all cell types, and are one of the first cell types of the BBB to degenerate in Alzheimer’s disease, Loss of pericytes can lead to BBB breakdown, causing a dysfunction in the transport regulation of blood-to-brain and brain-to-blood factors. Pericyte loss accelerates development of Alzheimer’s disease pathology including amyloid beta (Aβ) deposition, tau pathology, and neuronal loss.
Insulin Resistance
Insulin resistance exhibit decreased dopamine signaling and impairments in mitochondrial function,
Postnatal loss of the insulin receptor in astrocytes affects morphology, circuit connectivity, and mitochondrial function.
Insulin signaling in astrocytes also plays a role in potentiating release of dopamine.
Obesity directly link to the decrease of insulin BBB transport while at the same time Diabetes increases of insulin BBB transport leads to higher risk of being more obese.
And finally the decrease of the proper function of the BBB highly contributes to accelerating agin. (Extracted from frontiersin.org)
i realized its free.