Opera Medica et Physiologica

Modulating the Effect of Melatonin on Behavioral Responses of Rats in an Experimental Model of Inflammation

Abstract: 

The problem of the influence of inflammation on the processes of higher nervous activity is still relevant. In particular, it implies an analysis of the safety and effectiveness of biological regulators’ effects with neurotropic and immunomodulatory potential. The study examined the effects of Salmonella tiphy LPS on behaviour and cognitive function in adult male Wistar rats with different levels of melatoninergic system activity, using various tests. It was found that daily injection of LPS to rats of the group А (50 μg/kg, i.p.) for 10 days leads to the formation of a special pattern of behavior with a low level of tentative research activity in the presence of increased anxiety. The rats of the group В received combined exposure to LPS (50 μg/kg, i.p.) and melatonin (5 mg/kg, orally) distinguished a higher level of various variants of motor and research activity in conditions of relatively low anxiety in contrast to the rats of the group А. The paper discusses the features and mechanisms of the formation of "painful" behavior in an experimental model of inflammation, depending on the level of activation of the components of the melatoninergic system.