Reciprocal pathway between medullary visceral zone and hypothalamic supraoptic nucleus or paraventricular nucleus involved in hyperosmotic regulation.
In this study we try to simultaneously investigate the response of neurons and astrocytes of rats following hyperosmotic stimulation and test the possibility that the reciprocal pathways between medullary visceral zone (MVZ) and hypothalamic paraventricular nucleus (PVN) or supraoptic nucleus (SON). Hyperosmotic pressure animal model was established by administering 3% sodium chloride as drinking water to rats. The distribution and expression of the HRP retrogradely labeled neurons, Fos, tyrosine hydroxylase (TH) or vasopressin (VP) positive neuron and glial fibrillary acidic protein (GFAP) positive astrocytes in the MVZ, SON and PVN were observed by quadruplicate-labeling methods of WGA-HRP retrograde tracing combined with anti-Fos, TH (or VP) and GFAP immunohistochemical technique. Fos positive neurons within the MVZ, PVN and SON increased markedly. There were also a large number of GFAP positive structures in the brain and their distribution pattern was fundamentally similar or analogous to Fos positive neurons in the above-mentioned areas. The augmented GFAP reactivities took on hypertrophic cell bodies, thicker and longer processes. Quadruplicate immunohistochemical staining showed that a neuron could be closely surrounded by many astrocytes and they formed neuron-astrocytic complex (N-ASC). Fos+/TH+/HRP+/GFAP+ and Fos+/VP+/HRP+/GFAP+ quadruplicate labeled N-ASC could be found in the MVZ, PVN and SON, respectively. The present results indicated that the neurons and astrocytes might be very active following hyperosmotic pressure and N-ASC as a functional unit might serve to modulate osmotic pressure. There were reciprocal osmoregulation pathways between the MVZ and SON or PVN in the brain.
Yang
Zhijun
Z
Neuromedical Institute, Zhujiang Hospital of Southern Medical University, #253 Gongye Road, Guangzhou, China.
Rao
Zhiren
Z
Jiang
Xiaodan
X
Yuan
Hua
H
Duan
Li
L
Chen
Liangwei
L
Wang
Ying
Y
Xu
Ruxiang
R
Zeng
Yanjun
Y
D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009997:Osmotic Pressure / Q000187:drug effects / Q000502:physiology; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism* / Q000473:pathology; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012965:Sodium Chloride / Q000494:pharmacology; D013495:Supraoptic Nucleus / Q000378:metabolism* / Q000473:pathology; D014882:Water-Electrolyte Balance
D009419:Nerve Tissue Proteins; D016760:Proto-Oncogene Proteins c-fos; D012965:Sodium Chloride