[Functional difference between the magnocellular neurosecretory nuclei of the rat hypothalamus].
The supraoptic, paraventricular, and postoptic nuclei (SON, PVN, and PON, respectively) of the hypothalamus were studied under conditions of 3 months training of rats to hypoxia (exposure for 6 h daily in a low pressure chamber under 7600m of simulated altitude). All the three nuclei were activated during the first 5 days, and then the state of the SON cells normalized. Functional activity of the PVN and PON decreased (the nucleolar volume of the neurosecretory cells diminished to 70--80%, the amount of the neurosecretory substance in the cells and the posterior lobe of the hypophysis was reduced). Such a decreased activity of the PVN and PON persisted till the end of the experiment. A positive correlation of the thyroid epithelium height and the nucleolar volume of the PVN and PON cells was established for both the PVN (r=0.81, P less than 0.05) and the PON (r=0.82; P less than 0.05); no significant correlation was revealed for the SON (r=0.51; P less than 0.05). Thus, functional similarity of the PVN and the PON, and some peculiarities in the SON reaction under conditions of the experiment described was demonstrated.
D000818:Animals; D001931:Brain Mapping; D002466:Cell Nucleolus / Q000648:ultrastructure; D007031:Hypothalamus / Q000503:physiopathology* / Q000648:ultrastructure; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D009489:Neurosecretion; D010286:Paraventricular Hypothalamic Nucleus / Q000503:physiopathology; D051381:Rats; D013495:Supraoptic Nucleus / Q000503:physiopathology; D013961:Thyroid Gland / Q000503:physiopathology
O funktsional'nom razlichii krupnokletochnykh iader gipotalamusa u krys.