Synergistic effects of memantine and alpha7 nicotinic acetylcholine receptor agonist PHA-543613 to improve memory of aged rats.

BACKGROUND

Combination treatments based on pharmacological interactions at α7 nicotinic acetylcholine receptors (nAChRs) are promising therapeutic approaches for neurocognitive disorders.

METHODS

Here, we tested the cognitive efficacy of combinations of memantine with an α7 nAChR-selective agonist (PHA-543613) in naturally aged rats. Age-related changes in the expression of some key genes and proteins were also measured using quantitative polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA).

RESULTS

Aged rats showed marked cognitive decline in the novel object recognition test, and they also exhibited cholinergic changes such as mRNA upregulation of α7 nAChRs. Upregulation of interleukin-1β, macrophage inflammatory protein 1α, CX3CL1, intercellular adhesion molecule 1, and ciliary neurotrophic factor mRNA was also detected in aged rats. Combination treatment of memantine and PHA-543613 successfully alleviated the age-related decline of recognition memory of rats by exceeding the effects of the corresponding monotreatments.

CONCLUSIONS

Results indicate a positive interaction between memantine and PHA-543613, which also reflects a putative role of α7 nAChRs in the cognitive enhancer effects of memantine. These findings may facilitate the development of combination therapies for age-related neurocognitive disorders.