Disclosed are medicaments and methods for inhibiting brain inflammation and the cognitive memory loss attendant brain disease and damage in an animal. Status epilepticus, stroke and Alzheimer's disease are particular pathologies that are treated employing pharmaceutically acceptable preparations of the A1 exosomes. The preparations comprise an enriched population of A1 exosomes, such as exosomes derived from culture medium from mesenchymal stem cells. Medicaments and methods for inhibiting pattern recognition and/or memory impairment attendant a brain injury event or degenerative brain disease are also disclosed, comprising administering a pharmaceutically acceptable preparation of exosomes, particularly A1 exosomes, that are CD9- and that prevent the elevation of pro-inflammatory cytokines attendant a brain injury or disease.
