Brain serotonin levels and metabolism in the non-hibernating bulbectomized European hamster

Serotonin levels and turnover were measured in different brains areas of full bulbectomized and partially bulbectomized European hamsters and their controls. Full bulbectomized hamsters did not hibernate and ate more than the two other groups in which hibernation patterns were similar. The levels of serotonin were of the same magnitude in the three groups. The turnover rates were slower in amygdala and hypothalamus in the full lesioned animals. These results were discussed for their implications in the mechanism of entrance into hibernation.