REGENERATION OF HYPOTHALAMIC NERVE FIBRES IN GOAT

In goats kept for many weeks after interruption of the hypothalamo-neurohypo-physial tract by pituitary stalk section, the nerve fibres of this tract proximal to the lesion were found to have regenerated. The extent of the regeneration depended on the level of the transection. When the operative damage had been confined to the stalk, the regrowth of nerve fibres was very vigorous and a new, ectopic infundibular process developed in the median eminence. When the tract had been severed at a higher level, by damage to the median eminence, some regeneration oceurred but this was less extensive. In all eases the reinnervated areas contained abundant NSM. The new nerve fibres penetrated beyond the limits of the normal tract, invading pars tuberalis and the basal leptomeninges. Herring bodies were very numerous where vigorous growth of nerve fibres had occurred.The nerve cells of the supraoptic and paraventricular nuclei were much reduced in number, the cell loss being most severe after transection of the tract at a high level. © 1969 S. Karger AG, Basel.