Voluntary Consumption of Sodium Glutamate Solution as a Factor of Depression-Like Behavior in Adult Rats: an Experimental Study

INTRODUCTION: Use of sodium glutamate solution with food is a widely spread practice. The glutamate-ergic system has been shown to directly participate in the mechanisms of depression, however, up to the moment, no data have been found to evidence that use of sodium glutamate causes depression. AIM: To study the effect of intake of sodium glutamate on the formation of depression-like behavior in male rats. MATERIALS AND METHODS: Formation of depression-like behavior was evaluated in male rats of Wistar line with 230 g250 g weight at the beginning of the experiment in the situation of inescapable swimming according to the method of R. D. Porsolt, and of hanging by the tail according to T. A. Voronina. In the course of the experiment, the rats of the experimental group consumed 1.1% sodium glutamate solution daily for 30 days, the control animals drank water. During the experiment, the rats were kept in individual cages and had free access to water. The animals of the control group (n = 7) had only water in the drinking bowls. The animals of the experimental group (n = 7) were given water in one drinking bowl and 60 mМ (1.1%) sodium glutamate solution (Henan Lotus Flower Gourmet Powder Cо., LTD, China) in the other. RESULTS: Consumption of 1.1% sodium glutamate solution for 30 days led to reduction of the time of active movements and to increase in the number of periods of immobilization in animals in both tests. Besides, in the tests for depression-like behavior of animals, increased rhythmologic index of depression was found in the group of rats receiving sodium glutamate solution. CONCLUSION: Based on the results of study, it was found that chronic voluntary consumption of 60 mM (1.1%) sodium glutamate solution for 30 days provokes the formation of depression-like behavior in rats.