The Effects of Acute and Chronic Stresses on Vasotocin Gene Transcripts in the Brain of the Rainbow Trout (Oncorhynchus mykiss)
Autor: | D. R. Tipping, Andrew Levy, B. J. Gilchriest, L. Hake, Bridget I. Baker |
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Rok vydání: | 2001 |
Předmět: |
Cortisol secretion
endocrine system medicine.medical_specialty Endocrine and Autonomic Systems Endocrinology Diabetes and Metabolism Vasotocin In situ hybridization Adrenocorticotropic hormone Biology Cellular and Molecular Neuroscience chemistry.chemical_compound Endocrinology nervous system chemistry Parvocellular cell Internal medicine medicine Chronic stress Corticotropic cell Habituation |
Zdroj: | Journal of Neuroendocrinology. 12:795-801 |
ISSN: | 1365-2826 0953-8194 |
Popis: | Secretion of adrenocorticotropic hormone (ACTH) from the fish pituitary, which occurs in times of stress, is stimulated by several hypothalamic neuropeptides, one of which is arginine vasotocin (AVT). This study investigates whether gene expression for AVT is up-regulated during acute or chronic stress. Rainbow trout (Oncorhynchus mykiss) were subjected to one of two forms of acute stress-either 2 h confinement followed by 2 h recovery, or capture and transfer to low water for 2 min followed by 4 h recovery in their home tank before autopsy. In other experiments, these stresses were repeated daily for 5 or 6 days (chronic stress). Quantification of AVT transcript prevalence in the parvocellular and magnocellular neurones of the preoptic nucleus after in situ hybridization was used as a monitor of the AVT gene response to stress. The results showed that acute confinement, but apparently not brief low-water stress, significantly increased AVT transcript prevalence in a group of parvocellular perikarya. When applied repeatedly, both forms of stress caused habituation, such that the AVT hybridization signal remained at control or even lower levels despite elevated pro-opiomelanocortin transcripts in the corticotropes and raised plasma cortisol concentrations. The AVT hybridization signal in the magnocellular perikarya showed no significant response to either acute or chronic stress. The results support the idea that these parvocellular AVT neurones are involved in ACTH stimulation during acute stress, and that the system habituates to chronic stresses. |
Databáze: | OpenAIRE |
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