Existence of an endogenous circadian rhythm in fluorescent dye-labelled cells in hypothalamus cultures
Barbacka-Surowiak, G.
Folia Biologica 34(1): 73-83
1986
ISSN/ISBN: 0015-5497 PMID: 3732566 Document Number: 274736
The activity of single anterior hypothalamic neurons grown in vitro was measured every three hours over a twenty-four hour period (or more), by means of the fluorescent dye method with 3.3'-dihexyloxacarbocyanine iodide (concentration 1.17 .times. 10-6 M). Two kinds of circadian activity were detected. In one group of neurons the acrophases tended to assemble in the morning hours and in an other in late afternoon or early evening. A third group of cells failed to show any rhythmicity. It is believed that the endogenous periodicity of these cells indicate an important role played by the hypothalamus in controlling biological rhythms in mammals.