Mohammad Hossein Esmaeili; Mohammad Sofiabadi; Hashem Haghdost; Ayda Lotfi; Mahshid Najafi
Volume 22, Issue 5 , November and December 2015, , Pages 862-869
Abstract
Background & Objectives: Although benzodiazepine drugs have notably anxiolytic and amnesic properties, some of β-carbolines, as their inverse agonists, have a stimulating effect on the dopaminergic system and also increase dopamine levels in hippocampus, and could exert anxiogenic and learning-enhancing ...
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Background & Objectives: Although benzodiazepine drugs have notably anxiolytic and amnesic properties, some of β-carbolines, as their inverse agonists, have a stimulating effect on the dopaminergic system and also increase dopamine levels in hippocampus, and could exert anxiogenic and learning-enhancing actions. The goal of present study was to investigate the effects of benzodiazepine receptor inverse agonist Norharmane on memory retention of passive avoidance learning in rats.
Materials & Methods: 40 male wistar rats were divided into control, alcohol and norharmane groups. All rates were trained in a passive avoidance task (50Hz, 1mA, for 3sec). Alcohol (0.2ml) or Norharmane (0.5, 1, 2 mg/kg, i.p.) were injected immediately after training. Retention test was done 48h later. Memory retention of each animal was measured as latency takes to enter the dark chamber of the task.
results: After-training injection of Norharmane improves memory retention in a dose-dependent manner, So that the time spent in the light chamber area before entering to the dark area and Total time spent in the light chamber in the norharmane groups were more than control group. These times in the norharmane (2 mg/kg) group was significantly higher than control group (p<0.001)
Conclusion: According to the findings, Norharmane, as inverse agonists of benzodiazepine receptors in the low doses, through GABA receptors stimulation, improves memory retention and so may be useful for memory improvement.