| Project/Area Number |
14580721
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Nerve anatomy/Neuropathology
|
|---|
| Research Institution | University of Tsukuba |
|---|
Principal Investigator |
HISANO Setsuji University of Tsukuba, Basic Medical Sciences, Professor, 基礎医学系, 教授 (70136216)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NOGAMI Haruo University of Tsukuba, Basic Medical Sciences, Associate Professor, 基礎医学系, 助教授 (30119838)
|
|---|
| Project Period (FY) |
2002 – 2003
|
| Project Status |
Completed (Fiscal Year 2003)
|
| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2002: ¥1,900,000 (Direct Cost: ¥1,900,000)
|
|---|
| Keywords | Hypothalamus / Glutamate / Transporter / Neuroendocrine neuron / Stress / 体液調節 |
|---|
| Research Abstract |
To clarify a functional role of endogenous glutamate in hypothalamic peptidergic neurons, the present study analyzed phenotypes of neurons which express a vesicular glutamate transporter (VGLUT2), the ultrastructural localization of VGLUT2 in neurohypophysial terminals and changes of VGLUT2 gene expression in the paraventricular (PVN) and supraoptic (SON) nuclei by stressful stimuli. In situ hybridization combined with immunohistochemistry revealed VGLUT2 gene expression in neurons containing vasopressin, oxytocin, orexin or proopiomelanocortin of the rat hypothalamus, suggesting the presence of neurotransmitter glutamate in these peptidergic neurons. Double-label immunofluorescence staining demonstrated VGLUT2-staining in vasopressin-containing terminals of the rat neurohypophysis but this was unable to observe ultrastructurally because of the high background caused by the anti-VGLUT2 antiserum used. Quantitative in situ hybridization analysis with BAS5000 and NIH image demonstrated that gene expression of corticotropin-releasing hormone but not VGLUT2 was significantly upregulated in the PVN of mice exposed to restraint stress. In experiments of osmotic challenges in rats, VGLUT2 gene expression was upregulated throughout the PVN and SON of water-deprivation animals, whereas the expression in salt-loading (drinking of 2% NaCl) animals was upregulated only in particular subregions of these nuclei where vasopressin neurons are predominantly located. These changes in VGLUT2 gene expression induced by osmotic stimulations were statistically significant as compared with the expression level in the control animal (euhydrated rats). These results show the regulation of VGLUT2 expression at the transcription level, dependent on the status of hormonal secretion from the neurohypophysis, and suggest autocrine or paracrine modulation by endogenous glutamate for the peptide release in some, but not all, peptidergic neurons of the hypothalamus.
|
