Influence of MLC901 Alone and with Moderate Exercise on Pain Response Concurrent Due to Stress of Male Mice.

Background: Physical exercise is known to have a positive effect on pain responses induced by stress, while chronic stress causes a negative effect on cognitive abilities. Depending on the type, duration, and intensity of the stressor, it can induce analgesia or hyperalgesia. Furthermore, the beneficial effects of traditional Chinese medicine MLC901 on stress processes have been reported.

Swimming improves the emotional memory deficit by scopolamine via mu opioid receptors.

Aims: The aim of the present study was to investigate the effect of swimming exercise on elevated plus-maze (EPM)-associated memory deficit induced by intra-CA1 injection of scopolamine (a muscarinic acetylcholine receptor antagonist used to model Alzheimer's disease in rodents) in male mice. In addition, involvement of the mu opioid receptors in this phenomenon was investigated.

Main Methods: Bilateral guide cannulae were implanted to allow intra-CA1 microinjections.