BIOLOGY 3UU3 Lecture Notes - Camp-Dependent Pathway, Per1, Circadian Clock
9 Feb 2013
School
Department
Course
Professor
Document Summary
Rhythmic gene expression in pituitary depends in herterologous sensitization by the. Mammalian daily cycles are driven by a circadian clock. Clock is based on the cell-autonomous rhythmic expression of clock genes. Cycling expression of period 1 (a clock gene) in the pituatory gland depends on heterologous sensitization of the adenosine a2b receptor. This happens by the nighttime activation of the melatonin mt1 receptors. Eliminating melatonin suppresses the expression of period 1 and increases the release of prolactin from the pituitary. If gene expression in not temporally correct, cellular malfunction and disease can result. 24 hour rhythm is regulated by transcription/translation feedback loops. Period in humans in a transcription/translation feedback loop. Circadian rhythms are not limited to the cells of the scn, they can be found in many tissues, but with a delayed timing with respect to the scn. Peripheral rhythms dampen in vitro after a few cycles b/c they depend on neuronal and/or neuroendocrine signals from the scn.
