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Memory-enhancing activity of verapamil in murine models of stress


Anthony T. Eduviere
Lily O. Otomewo
Onoriode A. Udi
Adefunke O. Opajobi
Emuesiri G. Moke

Abstract

Purpose: To evaluate the benefit of verapamil on stress-induced memory impairment in mice.


Methods: Forty-eight (48) mice were used in this study. They were divided into two equal groups based on the two models of stress used  in this study (sleep deprivation and hypoxia). Each model was further divided into 4 groups of six animals each. The mice in the sleep  deprivation model were suspended on a platform above water while in the hypoxic model, mice were locked in an airless container for 20  min daily throughout the experiment. As for the intervention, 25 and 50 mg/kg verapamil were preadministered via the oral route to  study groups, except the normal control group and negative control group in both models. After seven-day stress and intervention, the  mice were subjected to behavioural tests (Y-maze and object recognition tests), biochemical assays (for acetylcholinesterase activity) and histochemical analysis.


Results: Stress caused a significant (p < 0.05) impairment in the consolidation and retrieval of working and  recognition memories. Also, acetylcholinesterase activity was significantly (p < 0.05) enhanced in the stressed groups when compared to  control groups. Similarly, the histological analysis revealed a significant decline in population (p < 0.05), distribution and density of viable  neurons in specific areas of the hippocampus and prefrontal cortex. These alterations were significantly (p < 0.05) attenuated in verapamil-treated groups almost in a dose-dependent pattern.


Conclusion: Verapamil displays significant memory-enhancing effects in  two (2) murine models of stress. Antihypertensives should therefore be considered a viable prospect in the management of stress-related  memory disorders after additional studies have been done to establish the mechanisms of action. 


Journal Identifiers


eISSN: 1596-9827
print ISSN: 1596-5996