Age-Related Changes in Blood-Brain Barrier ( BBB )

The BBB is a major modulator of nutrient delivery to the central nervous system ( CNS ) and a major keeper from environmental toxins. Any age-related deteriorations in the BBB may lead to brain damage and consequently to progressive deterioration and loss of memory. Some data have suggested that the BBB is broken down in Alzheimer’s disease,12 but no evidence supporting this view has been obtained by positron emission tomography ( PET ).9 Most of the studies reported so far have failed to show a significant age-related alteration in BBB permeability to water-soluble substances and high molecular weight solutes in the absence of neurological disease.6,8 We evaluated the brain uptake of serum albumin, the most common circulating macromolecule, in SAM-P/8 and SAM-R/1, as SAM-P/8 but not SAM-R/1 showed a marked age-deterioration in the ability of memory and learning in passive and active avoidance responses,5,10,11