GHRP-6
Growth Hormone Releasing Peptide-6, Growth hormone-releasing hexapeptide, His-D-Trp-Ala-Trp-D-Phe-Lys-NH2
Stimulation of neurogenesis in rat nucleus of the solitary tract by ghrelin.
Zhang. Weizhen W; Hu. Yuexuan Y; Lin. Theodore R TR; Fan. Yongyi Y; Mulholland. Michael W MW
Key Findings
- Systemic ghrelin increased BrdU labeling (a marker of cell division) in the rat NTS, indicating neurogenesis.
- In cultured NTS neurons, ghrelin raised the percentage of cells incorporating BrdU in a dose‑ and time‑dependent way.
- The neurogenic effect was blocked by ghrelin‑receptor antagonists (including D‑Lys‑3‑GHRP‑6) and reduced by an L‑type calcium channel blocker.
Practical Outcomes
- For biohackers, the study suggests ghrelin can stimulate brain cell growth, but the work is limited to rats and a specific brain region not directly tied to cognition or performance. It does not provide a clear dosing protocol for humans, nor does it show that GHRP‑6 (a ghrelin secretagogue) will have the same effect. Use this as a piece of mechanistic background rather than a direct guide for supplementation.
Summary
A study in rats found that giving ghrelin, a stomach hormone, can boost the creation of new nerve cells in a part of the brain called the nucleus of the solitary tract. The effect was seen both in live animals and in cultured brain cells, and it depended on dose and time. Blocking the ghrelin receptor stopped the effect, showing the action is direct.
Abstract
Ghrelin, a gastric hormone, regulates growth hormone secretion and energy homeostasis. The present study shows that ghrelin promotes neural proliferation in vivo and in vitro in the rat nucleus of the solitary tract (NTS). Systemic administration of ghrelin significantly increased 5-bromo-2'-deoxyuridine (BrdU) incorporation in the NTS in adult rats with cervical vagotomy. Cultured NTS neurons contain immature precursor cells as shown by expression of Hu protein. Exposure of cultured NTS neurons to ghrelin significantly increased the percentage of BrdU incorporation into cells in both dose- and time-dependent manners. Co-localization of Hu immunoreactivity with BrdU labeling was demonstrated by double fluorescent staining, suggesting that cells labeled with BrdU are neuronal cells. Ghrelin receptor mRNA was detected in tissues from the NTS. The mitotic effect of ghrelin was abolished by treatment of cultured NTS neurons with ghrelin receptor antagonists: D-Lys-3-GHRP-6 and [D-Arg1, D-Phe-5, D-Trp-7, 9, Leu-11] substance P. Diltiazem, a L-type calcium channel blocker, significantly attenuated ghrelin-mediated increments in BrdU incorporation. Ghrelin acts directly on NTS neurons to stimulate neurogenesis.
Study Information
pubmed
2005
2005-07-06T00:00:00.000Z
10.1016/j.peptides.2005.04.023
50
50