Experimental model of brain amyloidosis in old rats

An experimental model of brain amyloidosis, based on the widely known casein model, has been developed. In adult 8–10-month-old rats, the latter model reproduces amyloidosis of internal organs, but does not involve the brain. At the same time, in old (26–28-month-old) rats injection of sodium caseinate results in accumulations of amyloid not only in the vascular walls of the kidneys, heart, lien, and liver, but also in the walls of pial vessels and radial cortical arteries and, in more rare cases, in the walls of large vessels in the brain base. Together with the structural impairments, injections of sodium caseinate evoke considerable shifts of the parameters of background mass electrical activity in the basolateral amygdala, dorsal hippocampus, and parietal cortex. Relative content of slow and sometimes activity increased, while the share of high-frequency waves dropped. These changes were relatively moderate in adult rats, while they were much more pronounced in old rats. Investigation of behavioral phenomena showed that after injections of sodium caseinate the ability to memorize becomes suppressed, and manifestations of the depressive state are intensified. Combined injections of sodium caseinate and phenobollne, the stimulant of protein synthesis, resulted in the development of more intensive morphological and functional manifestations of amyloidosis in old rats.Neirofiziologiya/Neurophysiology, Vol. 28, No. 2/3, pp. 83–94, March–June, 1996.