Transplanted suprachiasmatic nucleus determines circadian period.
Level 5 - mechanism / opinion, no new human data
Preclinical animal interventional experiment
PubMed 2305266 · doi:10.1126/science.2305266
What was done
Neural tissue from the suprachiasmatic region of hamsters (including a mutant strain displaying a short circadian period) was transplanted into host hamsters rendered arrhythmic via suprachiasmatic nucleus ablation.
What was found
Transplantation of suprachiasmatic tissue restored overt circadian rhythms in ablated animals. The restored circadian period always reflected the genotype of the donor tissue rather than that of the host, independent of transplant direction. Specific quantitative values for period lengths and sample sizes were not reported in the abstract.
Why it matters
This establishes that the intrinsic period of the mammalian circadian pacemaker is autonomously dictated by donor cells within the suprachiasmatic nucleus.
Limits
The findings are derived entirely from a rodent model and cannot be directly generalized to clinical human physiology. The abstract provides no quantitative data, sample sizes, or information on variability and graft survival rates.
Cited by
- supports Transplanting the suprachiasmatic nucleus from one hamster into an SCN-lesioned arrhythmic hamster restores circadian behavioral rhythms.