PMID: 18756821
Agapova et al./PubMed/2008
Why It Matters
This paper caught my attention because it maps the precise timing and location of Semax's effects on two major neurotrophic factors. The opposing patterns (down in memory centers, up in executive function areas) within 20 minutes suggest Semax isn't just broadly "neuroprotective" — it's doing something specific and coordinated across brain regions. But this is animal data only, measuring gene expression changes, not actual cognitive outcomes in humans.
Key Findings
- Single intranasal dose of 50 mg/kg Semax caused opposite effects in different brain regions within 20 minutes — BDNF and NGF expression decreased in hippocampus but increased in frontal cortex
- Gene expression levels returned to baseline by 40 minutes, then surged again at 90 minutes, before returning to control levels by 8 hours
- The biphasic response pattern (initial change → baseline → secondary surge) suggests Semax triggers a coordinated regulatory program rather than a simple dose-response effect
- Both BDNF and NGF followed the same temporal pattern in each brain region, indicating the response mechanism may be shared between these growth factors
- The study used single-dose administration in rats — no data on chronic dosing, human equivalents, or whether gene expression changes translate to functional cognitive benefits
Read the Paper↗PMID: 18756821