Related Experiment Video
Updated: Aug 20, 2026
Restraint to Induce Stress in Mice and Rats
Published on: December 6, 2024
Orexin A promotes histamine, but not norepinephrine or serotonin, release in frontal cortex of mice
Zong-Yuan Hong1, Zhi-Li Huang, Wei-Min Qu
1School of Life Science, University of Science and Technology of China, Hefei 230027, China.
Aim:
To investigate the effects of orexin A on release of histamine, norepinephrine, and serotonin in the frontal cortex of mice.
Methods:
Samples for measuring histamine, norepinephrine, and serotonin contents were collected by in vivo microdialysis of the frontal cortex of anesthetized mice. The histamine, noradrenaline, and serotonin content in dialysates were measured by HPLC techniques.
Results:
Intracrebroventricular injection of orexin A at doses of 12.5, 50, and 200 pmol per mouse promoted histamine release from the frontal cortex in a dose-dependent manner. At the highest dose given, 200 pmol, orexin A significantly induced histamine release, with the maximal magnitude being 230% over the mean basal release. The enhanced histamine release was sustained for 140 min, and then gradually returned to the basal level. However, no change in norepinephrine or serotonin release was observed under application of the same dose of orexin A.
Conclusion:
These results suggest that the arousal effect of orexin A is mainly mediated by histamine, not by norepinephrine or serotonin.
