-
Article
New actions of melatonin and their relevance to biometeorology
Melatonin is not only produced by the pineal gland, retina and parietal but also by various other tissues and cells from vertebrates, invertebrates, fungi, plants, multicellular algae and by unicells. In plan...
-
Article
Circadian rhythmicity in the stimulation of bioluminescence by biogenic amines and MAO inhibitors inGonyaulax polyedra
In the dinoflagellateGonyaulax polyedra bioluminescence was investigated in constant darkness. Light emission was stimulated considerably and specifically by the biogenic smines epinephrine, 5-methoxytryptamine, ...
-
Article
Differential light effects on the dark motility rhythm inEuglena gracilis by series of short light pulses: Induction of long-term fluctuations and holding of the circadian oscillator
Dark motility was measured by means of an infrared beam in stationary, 8- to 10-months-old autotrophic cultures ofEuglena gracilis, strain Z. Controls in constant darkness exhibited circadian rhythms for several ...
-
Article
Ultradian rhythmicity of tyrosine aminotransferase activity inEuglena gracillis: Analysis by cosine and non-sinusoidal fitting procedures
Although the geophysical periodicity of the earth's rotation corresponds to a biological cyclicity of ca. 24 h, cellular temporal organization comprises a multifrequency time structure, in which ultradian rhyt...