Related Experiment Videos
Central melatonin receptors in red deer (Cervus elaphus)
L M Williams1, L T Hannah, C E Kyle
1Rowett Research Institute, Bucksburn, Aberdeen, United Kingdom.
General and Comparative Endocrinology
|October 1, 1996
Summary
Researchers mapped melatonin receptor sites in red deer brains and pituitary glands. These findings reveal key locations where melatonin influences seasonal changes, aiding in understanding neuroendocrine regulation.
Area of Science:
- Neuroendocrinology
- Neuroanatomy
Background:
- Seasonal changes in red deer (Cervus elaphus) are regulated by melatonin, a pineal hormone.
- Melatonin acts as a neuroendocrine transducer of photoperiod, influencing appetite, growth, and reproduction.
- Identifying central melatonin targets is crucial for understanding its physiological effects.
Purpose of the Study:
- To localize and characterize [2(-125)I]iodomelatonin binding sites in the cervine brain and pituitary.
- To investigate the potential G-protein-coupled nature of these binding sites.
Main Methods:
- In vitro autoradiography was used to map binding sites in brain and pituitary tissue.
- [2(-125)I]iodomelatonin was used as a radioligand.
- Competition assays with melatonin, N-acetylserotonin, and GTP gamma S were performed.
Main Results:
- Specific [2(-125)I]iodomelatonin binding was observed in the cortex, septum, putamen, hippocampus, cerebellum, superior colliculus, choroid plexus, pars tuberalis, and pars distalis.
- Binding was abolished by melatonin and inhibited by GTP gamma S in most regions, suggesting G-protein-coupled receptors.
- Binding characteristics (Kd in low picomolar range) were consistent with known melatonin receptors.
Conclusions:
- Melatonin receptors are widely distributed in the red deer brain and pituitary.
- These receptors are likely G-protein-coupled, mediating melatonin's effects on seasonal physiology.
- The findings provide a neuroanatomical basis for melatonin's influence on red deer biology.