Present address: Department of Surgery, Shanghai Pudong New Area People's Hospital, Shanghai 201200, China.
Long-term in vivo pineal microdialysis
Article first published online: 23 JUL 2003
Journal of Pineal Research
Volume 35, Issue 2, pages 118–124, September 2003
How to Cite
Sun, X., Liu, T., Deng, J. and Borjigin, J. (2003), Long-term in vivo pineal microdialysis. Journal of Pineal Research, 35: 118–124. doi: 10.1034/j.1600-079X.2003.00064.x
- Issue published online: 23 JUL 2003
- Article first published online: 23 JUL 2003
- Received February 3, 2003; accepted April 10, 2003.
- circadian rhythms;
- 5-hydroxytryptamine (serotonin);
- in vivo microdialysis;
- pineal gland;
- serotonin N-acetyltransferase
Abstract: This study describes the development of a new technique for long-term measurement of daily 5-hydroxytryptamine (5-HT) and melatonin contents in the pineal gland of freely moving rats. The technique features a number of novel improvements over previous protocols. It allows visualization of the pineal gland for accurate targeting of the guide cannula, which minimizes bleeding; incurs no direct injury to the surrounding brain tissues; and causes no interference with the sympathetic innervation from the superior cervical ganglia. Robust releases of melatonin and indole precursors were continuously monitored quantitatively and reproducibly for more than 2 wk in the same animal. In addition, effects of pharmacological agents on in vivo pineal circadian rhythms can be studied reproducibly over time, and gene expression profiles can be correlated with physiological consequences in single animals. Using these approaches, it is found that β-adrenergic activation leads to decreased release of 5-HT, and that increased cAMP signaling in vivo results in activation of N-acetyltransferase gene induction and melatonin production. These studies will enhance the understanding of signaling pathways that regulate pineal 5-HT and melatonin synthesis and secretion.