PSY397H1 Lecture Notes - Lecture 10: Talitridae, Circadian Rhythm, Circadian Clock
Document Summary
Lesions to the pineal gland eliminates circannual rhythmicity. Melatonin has been shown to synchronize rhythms in pups. Circadian rhythms of fetal and neonatal rodents are entrained by their mothers which depends upon the material scn. Administering melatonin to scn lesioned hamsters entrains activity rhythm of pups. Lesions to scn disrupt melatonin, removing this source of time of day information. Hence mothers with scn lesions produce desynchrony observed in litters born to scn lesions. Amphipods (beach hoppers) are intertidal crustaceans with worldwide distribution. Numerous experiments have been performed that look at sun compass orientation in the escape behavior of amphipods. There is a little confusion in the literature, but in general i has been found that the animals use local cues if they are available, and celestial cues (the sun) if local cues are not readily detectable. We will use the hartwick, 1976 article along with the hypothetical beach shown here to illustrate the general concepts.
