Effects of Morphine on Memory: Interactions with Naloxone, Propranolol and HaloperidolSaha N. · Datta H. · Sharma P.L.
Department of Pharmacology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
The effects of morphine on memory have been shown to be dependent on the strain of animal used and on the experimental parameters. Memory was assessed in a passive avoidance task using Swiss albino (ICRC) mice. Morphine at doses of 1 3 and 10 mg kg–1 was administered immediately after foot shock (memory retention) or 23.5 h after foot shock (memory retrieval). Retest step-down latencies measured 24 h later showed that morphine did not affect memory retention but dose-dependently impaired retrieval of memory. Administration of naloxone 0.1 mg kg–1 antagonised the effects of morphine and impaired memory retention. Propranolol 0.3 mg kg–1 along with morphine 3 mg kg–1 impaired memory retention only while haloperidol 0.1 mg kg–1 improved the impairment of memory retrieval caused by morphine 3 mg kg–1. Glucose did not alter the effects of morphine on memory. There was no per se effect of morphine, naloxone, propranolol, glucose and haloperidol on memory at the doses used. The effect of morphine on memory retention is mediated by opioid mechanisms; however, adrenergic and dopaminergic mechanisms possibly modulate retention and retrieval of memory, respectively.
© 1991 S. Karger AG, Basel
Dr. H. Datta, Additional Professor, Department of Pharmacology, PGIMER, Chandigarh 160012 (India)
Received: May 30, 1990
Accepted: August 16, 1990
Published online: June 06, 2008
Number of Print Pages : 5
Pharmacology (International Journal of Experimental and Clinical Pharmacology)
Vol. 42, No. 1, Year 1991 (Cover Date: 1991)
Journal Editor: Donnerer J. (Graz), Billingsley M.L. (Hershey, Pa.), Maeyama K. (Matsuyama)
ISSN: 0031–7012 (Print), eISSN: 1423–0313 (Online)
For additional information: http://www.karger.com/PHA