I. Introduction U NTIL 35 yr ago, most scientists did not take research on the pineal gland
seriously. The decade beginning in 1956, however, provided several discoveries that laid …

Melatonin is a molecule present in a multitude of taxa and may be ubiquitous in organisms. It
has been found in bacteria, unicellular eukaryotes, macroalgae, fungi, plants and animals. A …

Vanecek, Jiri. Cellular Mechanisms of Melatonin Action. Physiol. Rev. 78: 687–721, 1998.—
The pineal hormone melatonin is involved in photic regulations of various kinds, including …

In addition to the more or less static properties of the environ ment, plants and animals must
cope with its temporal variations. Among the most conspicuous temporal changes to which …

This review summarizes the evidence showing that the duration of the nocturnal secretory
profile of pineal melatonin (MEL) is critical for eliciting seasonally appropriate reproductive …

Breeds of sheep and goats from temperate latitudes exhibit seasonal variations of breeding
activity which are controlled by annual photoperiodic changes. Short days (SD) stimulate …

A seasonal distribution in human natural conception and birth rates has been consistently
demonstrated by epidemiological studies in several geographical areas. Possible …

Adaptation to the environment is essential for survival, in all wild animal species seasonal
variation in temperature and food availability needs to be anticipated. This has led to the …

There is a daily rhythm in the production of the pineal hormone melatonin in all mammalian
species. Production is stimulated by darkness and inhibited by light. This provides a signal …

Living organisms show seasonality in a wide array of functions such as reproduction,
fattening, hibernation, and migration. At temperate latitudes, changes in photoperiod …