Chronic stress is associated with cognitive impairment. It is possible that this is due to the brain's immune cells, microglia. Microglia can engulf and chew up neurons, which are the cells in the brain that talk to one another. It is possible that chronic stress makes these immune cells more likely to engulf neurons, which leads to cognitive deficits. To understand this, we will use live imaging to look at how microglia act in the brain of chronically stressed laboratory mice. We will then see if treatments that can reverse chronic stress induced cognitive deficits, such as probiotics, cannabinoids, omega-3 supplementation or ketogenic diet, work through altering these brain immune cells (microglia). Together these data will better inform how chronic stress leads to alterations in cognition and may provide a new target for therapeutics of cognitive deficits observed in stress-associated disorders, including depression and anxiety disorders.