Related Experiment Video
Updated: Jul 29, 2026

Recording and Analysis of Circadian Rhythms in Running-wheel Activity in Rodents
Published on: January 24, 2013
Pulses of cholinergic receptor escape from atropine blocking reflect major natural periodicities
Abstract:
1. Semi-lunar variation in cardiac response to applied acetylcholine was reconfirmed. 2. Atropine completely blocked the effects of acetylcholine on the heart except for brief pulses of escape at 12-hr intervals which began at moonset and progressed through midday at 10 to 14-day intervals. 3. The direction of escape, i.e. inhibition or acceleration, reversed at the winter solstice and at both equinoxes. 4. Cholinergic receptors in the cardiac preparation seem to reflect the following: 12-hr intervals beginning at moonset, 24.8 hr. 10 to 14-day intervals, 14.8-day intervals and the equinoxes and solstices. 90-day intervals.
Related Concept Videos
Cholinergic Receptors: Muscarinic
The subtypes M1, M3, and M5 couple with the Gq subunit and activate the phospholipase C (PLC) activity, mobilizing intracellular Ca2+. Activation...
Direct-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
The direct-acting...
Direct-Acting Cholinergic Agonists: Pharmacokinetics
Direct-Acting Cholinergic Agonists: Pharmacological Actions
Cholinergic Antagonists: Chemistry and Structure-Activity Relationship
Parasympathetic Signaling
The effects of...

