AJP - Regulatory, Integrative and Comparative Physiology, Vol 251, Issue 4 755-R761, Copyright © 1986 by American Physiological Society
Does serotonin play a role in entrance into hibernation?
B. Canguilhem, J. L. Miro, E. Kempf and P. Schmitt
To study the role of brain serotonin in entrance into hibernation,
intraventricular injections of 5,7-dihydroxytryptamine, electrolytic
lesions of small parts of the median raphe nucleus, and chemical lesions of
the same nucleus were undertaken on the European hamster in winter. All the
lesions led to a variable decrease of serotonin levels in all parts of the
brain areas examined. However, hibernation was suppressed only in those
animals whose serotonergic neurons were destroyed in a small anterior part
of the median raphe nucleus. Electrolytic lesions as well as chemical
lesions in the other parts of the median raphe nucleus or the
5,7-dihydroxytryptamine injections into lateral ventricles do not prevent
hibernation. These data suggest that in the European hamster only a
specific group of serotonergic neurons of the median raphe nucleus are
involved in the process of entrance into hibernation.
