The ubiquity of circadian rhythms in living organisms has generally been accepted by
researchers over the last century. Indeed, morphology and molecular biology of the …

Nonmammalian vertebrates have been known to have photoreceptors in their pineal
complex and deep brain as well as the retina. The extraretinal photoreceptors are believed …

The present review is a detailed survey of our present knowledge of the centrifugal visual
system (CVS) of vertebrates. Over the last 20 years, the use of experimental hodological and …

The hamster suprachiasmatic nucleus (SCN), site of the circadian clock, has been thought to
be equally and completely innervated by each retina. This issue was studied in animals that …

All organisms exhibit significant daily rhythms in a myriad of functions from molecular levels
to the level of the whole organism. Significantly, most of these rhythms will persist under …

The pineal gland and its hormone melatonin are crucial for the generation of circadian
rhythms in several species of passerine birds. The sites and mechanisms by which they …

Many lines of evidence support the hypothesis that the circadian system regulates vision in
birds; however, the mechanism of this regulation is completely unknown. The present …

In many species of vertebrates the pineal gland and its indoleamine hormone melatonin
play central roles in the control of circadian rhythms, whereas in some species, the pineal …

The avian circadian rhythm pacemaker is composed of the retina, pineal gland and
suprachiasmatic nucleus. As an intact input-pacemaker-output system, each of these …

Daily rhythms are a fundamental feature of all living organisms; most are synchronized by
the 24hr light/dark (LD) cycle. In most species, these rhythms are generated by a circadian …