https://www.foxnews.com/health/some-80-year-olds-still-have-razor-sharp-brains-now-scientists-know-why if you zoom in specifically on the hippocampus, there are a few human IV-ketamine-in-depression studies that look directly at: hippocampal volume / subfields, and hippocampus functional connectivity (resting-state FC), and hippocampus activation during emotional/cognitive tasks. Here are the most on-point ones for a standard IV ketamine clinic–style dose (0.5 mg/kg over ~40 min): 1)...

Inducing Synaptic Plasticity in the Treatment of Cognitive Dysfunction Ketamine was originally introduced into clinical medicine as an anesthetic. It had significant benefits. Namely, it produced a profound analgesia without the respiratory depression associated with other anesthetic medications. Ketamine, however, does cause other effects through its action on a wide array of brain receptor sites. Some of these receptor variants cause cognitive, psychotropic, and emotional side effects...