[The effect of factors of the supraoptic and paraventricular hypothalamic nuclei on the growth, cellular reproduction and cytodifferentiation of the adenohypophyseal epithelium]. / Vliianie faktorov supraopticheskikh i paraventrikuliarnykh iader gipotalamusa na rost, kletochnuiu reproduktsiiu i tsitodifferentsirovku épiteliia adenogipofiza.

In hypophysectomised noninbred [correction of inbred] rats and in male rabbits, a direct influence of stimulation with oxytocin, vasopressin, dopamine of the hypophysis substance's adenocytes enhanced their proliferation as well as the DNA synthesis. The role of hypothalamic nonapeptides as the regulators of cells and tissues homeostasis is discussed.

Specificity of circadian function in transplants of the fetal suprachiasmatic nucleus.

Fetal tissues obtained from specific regions of the developing hypothalamus were transplanted to determine whether the precursor neurons of the suprachiasmatic nucleus (SCN) can be distinguished from those of the presumptive paraventricular nucleus (PVN) on the basis of the functional capacity to generate circadian rhythms. The presumptive SCN, the PVN, and a portion of the neocortical primordium were dissected from the developing forebrains of normal Long-Evans fetuses, separated, and selectively transplanted into the periventricular-third ventricle region of adult, vasopressin (VP)-deficient Brattleboro rats. In host animals that received grafts containing the precursor population of SCN neurons, the temporal profile of VP levels in the cerebrospinal fluid (CSF) oscillated with a circadian periodicity in a manner similar to that observed in normal Long-Evans rats. CSF collected serially from animals with grafts of the presumptive PVN also contained VP, but no circadian variation was manifested in peptide levels. VP was undetectable in CSF samples obtained from Brattleboro rats with cortical grafts. In association with their circadian functional capacity, grafts of the SCN primordium were characterized by clusters of parvicellular neurons immunopositive for VP or vasoactive intestinal polypeptide (VIP) that resembled the cell groups of the in situ SCN. In contrast, transplants of the presumptive PVN did not contain neurons immunoreactive for VIP, and the VP neurons in these grafts resembled the neurosecretory cells of the PVN.(ABSTRACT TRUNCATED AT 250 WORDS)

A procedure for small-volume brain grafting; vasopressin cells in neonatal and adult Brattleboro rats.

A simple and reliable technique is described for the transplantation of fetal vasopressin (VP) neurons in the third ventricle of the brain of homozygous Brattleboro neonates. Small-volume grafting is introduced by microdissection of paraventricular and supraoptic areas and by pelleting the minced tissue for insertion into the transplantation cannula. Morphological and immunocytochemical evaluation yielded results in both neonatal and adult host brain that were similar to those described for anterior hypothalamic grafts in adult Brattleboro brain. The present protocol circumvents some of the general problems encountered when the use of small grafts is imperative, and is also applicable to the implantation of pelleted cell suspensions.