[Restoration of circadian rhythmicity after transplantation of the suprachiasmatic nucleus in the rats--its conditions for functional recovery and long-term survival].
Whole tissue grafts of day 1 neonatal or day 21 embryonic suprachiasmatic nuclei (SCN) in rats transplanted into host's third ventricle restored circadian rhythmicity in 8 cases out of 18 SCN-lesioned arrhythmic rats. Restored circadian rhythmicity had been observed for maximum 14 months after the transplantation. Immunohistochemical staining (Vasoactive intestinal polypeptide: VIP and vasopressin) confirmed the survival of the transplanted SCN tissues within the host's third ventricle. This may be the case of the longest-term survival of functioning SCN grafts which connected with the host's brain by neurites after transplantation. This finding may be a promising support for clinical application of neural tissue transplantation. In contrast, rhodamine-labeled SCN cell suspension transplanted into host's third ventricle did not restore circadian rhythmicity in 24 cases. Histological analysis revealed aggregated donor cells attached to the third ventricle and immunocytochemically stained with both VIP and vasopressin. Furthermore, rhodamine within the host brain suggested the fiber connections between the host and the donor cells. This result indicated that the circadian oscillator in SCN may function only based on the structural integrity of the SCN.
Kuroiwa
A
A
Department of Neurosurgery, Tokyo University, Japan.
Saitoh
Y
Y
Nihonmatsu
I
I
Kawamura
H
H
Takakura
K
K
D000818:Animals; D016380:Brain Tissue Transplantation; D002940:Circadian Rhythm; D006085:Graft Survival; D007150:Immunohistochemistry; D051381:Rats; D013493:Suprachiasmatic Nucleus / Q000378:metabolism / Q000502:physiology*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism; D014667:Vasopressins / Q000378:metabolism
D014667:Vasopressins; D014660:Vasoactive Intestinal Peptide