Dihydromyricetin improves social isolation-induced cognitive impairments and astrocytic changes in mice

Abstract

Social isolation induces stress, anxiety, and mild cognitive impairment that could progress towards irreversible brain damage. A probable player in the mechanism of social isolation-induced anxiety is astrocytes, specialized glial cells that support proper brain function. Using a social isolation mouse model, we observed worsened cognitive and memory abilities with reductions of Object Recognition Index (ORI) in novel object recognition test and Recognition Index (RI) in novel context recognition test. Social isolation also increased astrocyte density, reduced astrocyte size with shorter branches, and reduced morphological complexity in the hippocampus. Dihydromyricetin, a flavonoid that we previously demonstrated to have anxiolytic properties, improved memory/cognition and restored astrocyte plasticity in these mice. Our study indicates astrocytic involvement in social isolation-induced cognitive impairment as well as anxiety and suggest dihydromyricetin as an early-stage intervention against anxiety, cognitive impairment, and potential permanent brain damage.

Barrier–environment interactions along the gut–brain axis and their influence on cognition and behaviour throughout the lifespan

“… 93 A further study suggests that isolation impairs astrocytic connectivity, reducing cell body volume and process complexity. 94 Although it has not been directly studied, socialization-related adaptations in these cells likely modify function of the neurovascular unit and BBB integrity to influence behavioural changes. 95 In brain endothelial cells, models of social stress, including social isolation and social defeat stress, lead to dysregulation of tight junction proteins and subsequent loss of BBB integrity in both male and female mice.…”