Photoperiodic response of the hypothalamo-pituitary-gonad axis in male and female canaries,Serinus canaria
| Autor: | Thomas P. Hahn, Gregory F. Ball, Era K. Hanspal, Natalie C. Audage, George E. Bentley |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Male
Hypothalamo-Hypophyseal System endocrine system medicine.medical_specialty Gonad Photoperiod Cell number Pituitary-Adrenal System Zoology Cell Count Molting Photostimulation Gonadotropin-Releasing Hormone Songbirds Song control system biology.animal Internal medicine Testis medicine Animals Female gonad photoperiodism biology Reproduction Ovary General Medicine Endocrinology medicine.anatomical_structure Female Animal Science and Zoology Fiber density Serinus canaria hormones hormone substitutes and hormone antagonists |
| Zdroj: | Journal of Experimental Zoology. :143-151 |
| ISSN: | 1097-010X 0022-104X |
| DOI: | 10.1002/jez.a.10245 |
| Popis: | Although the gonadal photoperiodic response and its influence upon the song control system in canaries have been extensively studied, photoperiodic regulation of the GnRH system has not been investigated. To examine the relationship between photoperiod and the reproductive neuroendocrine system in male and female canaries, three groups of canaries were exposed to chronic short days (8L:16D; Phsens), acute long days (18L:6D; Phstim) and chronic long days (also 18L:6D; Phrefr) to induce the reproductive states of photosensitivity, photostimulation, and photorefractoriness, respectively. Brain sections were processed for GnRH immunocytochemistry. The canaries in this study did not demonstrate consistent or uniform responses to different photoperiodic treatments. In males, gonad size varied with photoperiod; Phstim males had larger gonads than either the Phsens or Phrefr males. In contrast, there was no difference between groups in female gonad size as a result of photoperiodic treatment. Brain GnRH cell number, cell size, and fiber density were similar in all groups. The results suggest that canaries are not as obligatory photoperiodic as previously thought (or at least not all varieties of domestic canaries are). This could be a result of many years of domestication, the natural history of the species, phylogenetic constraint, or a combination of these factors. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|