Paper Information

Title: 

THE IMPAIRING EFFECTS OF GLUCOCORTICOIDS ON MEMORY RETRIEVAL REQUIRE ACTIVATION OF DOPAMINE D2 RECEPTOR IN THE PREFRONTAL CORTEX

Type: POSTER
Author(s): PAKDEL R.,RASHIDIPOUR A.,VAFAEI ABAS ALI
 
 
 
Name of Seminar: IRANIAN CONGRESS OF PHYSIOLOGY AND PHARMACOLOGY
Type of Seminar:  CONGRESS
Sponsor:  PHYSIOLOGY AND PHARMACOLOGY SOCIETY, MASHHAD UNIVERSITY OF MEDICAL SCIENCE
Date:  2007Volume 18
 
 
Abstract: 

Introduction: Previous studies indicated that glucocorticoids impair retrieval of spatial and contextual memories in both humans and animals, but the underling mechanisms are not known. This study investigated glucocorticoid-dopaminergic interactions in modulating retrieval of long term memory in an inhibitory avoidance task.
Methods: Young adult male rats were trained in one trial inhibitory avoidance task (0.5 mA, 3 s footshock). On the retention test given 48 h after training, the latency to re-enter the dark compartment of the apparatus was recorded. All drugs were injected 30-60 min before retention test.
Results: Systemically administered corticosterone (1 or 3 mg/kg) given to rats thirty min before retention testing impaired their memory retrieval, but the lower dose was more effective than the higher one. Administration of the dopamine (DA) D2 receptor antagonist sulpiride (6 or 20 mg/kg) 30 min before corticosterone attenuated the impairing effects of corticosterone (1mg/kg) on memory retrieval. Administration of the DA D1 receptor antagonist SCH23390 (25 or 50 µg/kg) had no effect on corticosterone-induced impairment of memory retrieval. Bilateral micoinjections of the DA D2 receptor antagonist sulpiride (10 or 100 ng/0.5ul per side) into the mPFC 30 min before corticosterone attenuated the glucocorticoid-induced impairment of memory retrieval. Further, applied doses of sulpiride or SCH23390 alone were ineffective in modulating memory retrieval.
Conclusion: These findings provide evidence for the existence of an interaction between glucocorticoids and DA D2 receptor located in the mPFC on memory retrieval process .

 
Keyword(s): 
 
Yearly Visit 26   tarjomyar
 
Latest on Blog
Enter SID Blog