Aging is associated with cognitive decline and accumulation of senescent cells in various tissues and organs. Senolytic agents such as dasatinib and quercetin (D+Q) in combination have been shown to target senescent cells and ameliorate symptoms of aging-related disorders in mouse models. However, the mechanisms by which senolytics improve cognitive impairments have not been fully elucidated particularly in species other than mice. To study the effect of senolytics on aging-related multifactorial cognitive dysfunctions we tested the spatial memory of male Wistar rats in an active allothetic place avoidance task. Here we report that 8 weeks treatment with D+Q alleviated learning deficits and memory impairment observed in aged animals. Furthermore, treatment with D+Q resulted in a reduction of the peripheral inflammation measured by the levels of serum inflammatory mediators (including members of senescent cell secretome) in aged rats. Significant improvements in cognitive abilities observed in aged rats upon treatment with D+Q were associated with changes in the dendritic spine morphology of the apical dendritic tree from the hippocampal CA1 neurons and changes in the level of histone H3 trimethylation at lysine 9 and 27 in the hippocampus. The beneficial effects of D+Q on learning and memory in aged rats were long-lasting and persisted at least 5 weeks after the cessation of the drugs administration. Our results expand and provide new insights to the existing knowledge associated with effects of senolytics on alleviating age-related associated cognitive dysfunctions.
Keywords: SASP; aging; brain; cognition; hippocampus; memory; plasticity; senescence.