Is the knife-cut in the hypothalamus a permanent barrier to regrowth of nerve fibers? -an affirmative answer.
The regenerative capacity of nerve fibers was studied in adult female rats. Horseradish peroxidase was injected into the anterior hypothalamus lateral to the suprachiasmatic nucleus 4 days, 6 weeks and 4 months, respectively, following an archiform retrochiasmatic knife-cut. The trajectory of the stained fibers was examined on horizontal sections of the hypothalamus. No nerve fibers could be seen sprouting across the scar-tissue of the knife-cut regardless of the survival time. In one rat (6-week survival time) a bundle of fine nerve fibers turned in a medial direction at the caudal end of the knife-cut, suggesting that sprouting fibers were destined to reinnervate parts of the deafferented medial-basal hypothalamus.
D000818:Animals; D001370:Axonal Transport; D005260:Female; D006735:Horseradish Peroxidase; D007031:Hypothalamus / Q000502:physiology*; D009416:Nerve Regeneration; D051381:Rats; D011919:Rats, Inbred Strains
D006735:Horseradish Peroxidase