Ultrastructure of junction areas between neurons and astrocytes in rat supraoptic nuclei.
OBJECTIVE
To determine the ultrastructure of junction areas between neurons and astrocytes of supraoptic nuclei in rats orally administered 30 g/L NaCl solution for 5 days.


METHODS
The anti-connexin (CX) 43 and anti-CX32 double immunoelectromicroscopic labeled method, and anti-Fos or anti-glial fibrillary acidic protein (GFAP) immunohistochemistry were used to detect changes in the junctional area between neurons and astrocytes in supraoptic nuclei of 5 rats after 30 g/L NaCL solution was given for 5days.


RESULTS
A heterotypic connexin32/connexin43 gap junction (HGJ) between neurons and astrocytes (AS) in rat supraoptic nuclei was observed, which was characterized by the thickening and dark staining of cytomembranes with a narrow cleft between them. The number of HGJs and Fos like immunoreactive (-LI) cells was significantly increased following hyperosmotic stimuli, that is, the rats were administered 30 g/L NaCl solution orally or 90 g/L NaCl solution intravenously. HGJs could be blocked with carbenoxolone (CBX), a gap junction blocker, and the number of Fos-LI neurons was significantly decreased compared with that in rats without CBX injection, while Fos-LI ASs were not affected.


CONCLUSIONS
HGJ may be a rapid adaptive signal structure between neurons and ASs in response to stimulation.
Duan
Li
L
Institute of Neurosciences, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China. zrrao@fmmu.edu.cn
Yuan
Hua
H
Su
Chang-Jun
CJ
Liu
Ying-Ying
YY
Rao
Zhi-Ren
ZR
D000818:Animals; D000897:Anti-Ulcer Agents / Q000494:pharmacology; D001253:Astrocytes / Q000648:ultrastructure*; D002229:Carbenoxolone / Q000494:pharmacology; D018031:Connexin 43 / Q000032:analysis / Q000276:immunology; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis / Q000276:immunology; D007365:Intercellular Junctions / Q000737:chemistry / Q000187:drug effects / Q000648:ultrastructure*; D008297:Male; D016253:Microscopy, Immunoelectron; D009474:Neurons / Q000648:ultrastructure*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013495:Supraoptic Nucleus / Q000166:cytology*
D000897:Anti-Ulcer Agents; D018031:Connexin 43; D005904:Glial Fibrillary Acidic Protein; D002229:Carbenoxolone