Cognitive Resilience in advanced aged suggests benefits from K-infusion on hippocampus neuroplasticity

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:

1. hippocampal volume / subfields, and

2. hippocampus functional connectivity (resting-state FC), and

3. 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) Hippocampal volume + subfields after a course of IV ketamine

Repeated infusions (clinic-like series)

• Zhou et al., 2020 (Translational Psychiatry): 44 MDD patients got six subanesthetic ketamine infusions; they reported volume increases in the right hippocampus and specific hippocampal subfields (notably CA4 and dentate gyrus–related layers; plus other subfield signals). 

  
  

  Why it matters: This is one of the clearest “hippocampus structure changes after serial IV ketamine” papers.

• Zavaliangos-Petropulu et al., 2023 (Frontiers in Psychiatry / PMC): TRD patients receiving serial ketamine; they specifically analyze hippocampal subfield volumes and relate baseline subfields to changes in depressive symptoms and neurocognitive performance. 

  
  

  Why it matters: It links hippocampal subfields to both symptom change and cognitive measures