Volume 6, Issue 3 (Summer 2015 -- 2015)                   BCN 2015, 6(3): 155-162 | Back to browse issues page

XML Print


1- Laboratory of Learning and Memory, Department and Research Center of Physiology, School of Medicine, Semnan University of Medical Sciences, 15131-38111, Semnan, Iran.
2- Semnan University of Medical Sciences
Abstract:  
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.
Type of Study: Original | Subject: Cognitive Neuroscience
Received: 2014/11/2 | Accepted: 2015/04/18 | Published: 2015/07/1

Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.