Problems in Interpreting the Effects of Drugs on Circadian Rhythms
The aim of this chapter is to provide a guide to some of the questions that might be raised when a drug is found to have effects on the temporal profile of variables. It discusses possible explanations, especially those involving the newly discovered major influence that behaviour can have on rhythms. Some people, of course, will be more concerned with learning whether or not a drug produces a desired temporal effect; discussion about whether the effect represents masking or entrainment, or whether an agent is a true zeitgeber or not, may seem academic. It is no more so than knowing whether an agent is an agonist or a partial agonist. In the long run medicine can be improved if the complexities of the circadian system are taken into account, and if the mode and site of the actions of chronobiotic drugs are understood.
KeywordsCircadian Rhythm Suprachiasmatic Nucleus Circadian System Circadian Time Phase Response Curve
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