Confocal Images of The Colocalization and Upregulation of Vasotocin and Galanin After Water Deprivation in Roosters

Abstract

The aim of this study was to investigate the effects of dehydration on galanin and vasotocin colocalization and galanin expression in the hypothalamo-neurohypophysial system. Adult (age: 22 to 35 weeks) roosters were used and deprived of drinking water for 48 hours in this study. The effects of dehydration were examined by measuring plasma osmolality, plasma levels of potassium, sodium and plasma vasotocin concentration. Double staining immunohistochemistry combined with confocal laser microscopy was utilized to determine the effects of dehydration on hypothalamic magnocellular neurons in the supraoptic and paraventricular nucleus and to verify the extend of colocalization. The results indicate that 48 hours water deprivation caused a moderate dehydration and significantly elevation of plasma osmolality, plasma sodium and vasotocin concentration. Furthermore, the colocalization of galanin and vasotocin was imaged in response to water deprivation only in supraoptic nucleus of hypothalamus. In this study, a close functional link between galanin and vasotocin neurons was found in all dehydrated animals. The simultaneous upregulation and the colocalization of these peptides in response to water deprivation may indicate a site specific control of vasotocin by galanin.

Keywords

• Colocalization,Galanin,Vasotocin,Water Deprivation

References

1. 1. Arad Z, Arnason SS, Chadwick A, Skadhauge E (1985): Osmotic and homonel response to heat and dehydration in the fowl, J Comp Physiol, 155, 227-234
2. 2. Chaturvedi CM, Chawdhurya A, Cornett LE (2001): Water deprivation and circadian changes plasma arginine vasotocin and mesotocin in the domestic hen, Chonoiology International, 18, 947-956.
3. 3. Ciosek J (2000): Vasopressin and oxytocin release from the neurohypophysis, Endocrinol Pol, 51, 113-123.
4. 4. Gundlach AL, Burazin TC (1998): Galanin- galanin receptor system in the hypothalamic, paraventricular and supraoptic nuclei, Ann NY Acad Sci, 863, 241-251.
5. 5. Jurkevich A, Barth SW, Kuenzel WJ, Köhler A, Grossmann R (1999): Development of sexuality dimorphic vasotocincinergic system in the bed nucleus of stria terminalis, J Comp Neurol, 408, 46-60.
6. 6. Klein S, Jurkevich A, Grossmann R (2006): Sexually dimorphic immunoreactivity cells and fibers in the canary brain, J Comp Neurol, 263, 347-364.
7. 7. Koike TI, Shimada K, Cornett LE (1986): Plasma levels of ımmunoreactive mesotocin and vasotocin during oviposition in chickens: relationship to oxytocin action of the peptides in vitro and pepetides interaction with myometrial membrane binding sides, Gen Comp Endocrinol, 70, 119-126.
8. 8. Kuenzel WJ, Masson M (1988): A stereotactic atlas of brain of the chick.1-166, In: John Hopkins University Press, Baltimore, Maryand.

9. 9. Ludwig M (1988): Dendritic release of vsopressin and oxytocin, J Neuroendocrinol, 10, 881-895.
10. 1010. Merchenthaler I, Lopez FJ, Negro-Vilar A (1993): Anatomy and physiology of cenral galanin-containing pathways, Progress in Neurobiology, 40, 711-769.
11. 11. Morris JF, Budd TC, Epton MJ, Ma D, Pow DV, Wang H (1998): Functions of perikaryon and denrites in mgnocellular vasopressin secterion neurons, Prog Brain Res, 119, 21-30.
12. 12. Mühlbauer E, Hamann D, Xu B, Ivell R, Ellendorf F, Grossmann R (1992): Arginine-vasotocin gene expression during osmotic challenge in the chicken, J Neuroendocrin, 4, 347-351.
13. 13. Nouwen EJ, Decuypere E, Kühn ER, Michels H, Hall TR (1984): Effects of dehydration, hemorrhage and oviposition on serum concentration of vasotocin, mesotocin and prolactin in th chicken, J Endocrinol, 102, 345-355.
14. 14. Palkovits M, Rökaeus L, Antoni FA, Kiss A (1998): Glanin in the hypothamo-neurohypophysial system. Neuroendocrinology, 46, 417-423.
15. 15. Pow DV, Waro AR, Morris JF (1995): Dendrites of hyothalamic magnocellular neurons release neurohypophyseal peptides by exocytosis, Neuroscience, 32, 435-439.
16. 16. Roberts MM, Robinson AG, Hoffmann GE, Fitzsimmons MD (1991): Vasopressin transort to the synthesis regulatin is coupled rate, Neuroendocrinology, 53, 416-422.
17. 17. Stallone JN, Braun EJ (1986): Regulation of plasma arginine vasotocin in conscious water-deprived osmotic fowl, J Physiol, 250, 644-664.
18. 18. Wang H, Ward AR, Morris JF (1995): Oestradiol acutely stimulates exocytosis of oxytocin and magnocellular neuron, Neuroscience, 68, 1179-1188.