Related Experiment Video
Updated: Mar 25, 2026
Disrupting Reconsolidation of Fear Memory in Humans by a Noradrenergic β-Blocker
Published on: December 18, 2014
Glucocorticoids Interact with Cholinergic System in Impairing Memory Reconsolidation of an Inhibitory Avoidance Task
Somayeh Amiri1, Zahra Jafarian1, Abbas Ali Vafaei1
1Laboratory of Learning and Memory, Physiology Research Center, Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran.
Introduction:
Recent studies suggest that glucocorticoids modulate memory reconsolidation. Moreover, cholinergic system is involved in memory reconsolidation. Since glucocorticoids interact with brain cholinergic system in modulating memory processing, we investigated whether glucocorticoid influences on the reconsolidation of emotionally arousing training depend on the cholinergic system.
Methods:
Mice were trained (1mA, 3s footshock) in an inhibitory avoidance task. Forty-eight hours after training, memory reactivation was occurred (Test 1), and different treatments were given. Two (Test 2), five (Test 3), and seven days (Test 4) after memory reactivation (Test 1), animals were retested for fear memory retention.
Results:
In the first experiment, we observed that administration of corticosterone (CORT, 0.3, 1 and 3 mg/kg) following memory reactivation impaired subsequent expression of memory in a dose-dependent manner. In the second experiment, we found that CORT-induced impairment of memory reconsolidation was reversed by the muscarinic receptor antagonist atropine (0.5 and 2 mg/kg). In the third experiment, the nicotinic receptor antagonist mecaylamine (0.5 or 2 mg/kg) was not able to block the corticosterone response.
Discussion:
These findings indicate that glucocorticoids impair memory reconsolidation by a muscarinic cholinergic mechanism.
Related Concept Videos
01:30Cognitive Enhancers: Cholinesterase Inhibitors and NMDA Receptor Antagonists
01:30Indirect-Acting Cholinergic Agonists: Pharmacological Actions
At the neuromuscular junction, these agents work by inhibiting the breakdown of acetylcholine, allowing it to remain bound to the receptor and bind to nearby receptors. This process leads to repetitive firing of the endplate, causing muscle...
01:18Indirect-Acting Cholinergic Agonists: Mechanism of Action
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex,...