Inhibitory Effect of NMDA Receptors in the Ventral Tegmental Area on Hormonal and Eating Behavior Responses to Stress in Rats

Abstract

Background. Stress and its consequences are among the causes of accidents. Objective. The effects of intraventral tegmental area (I-VTA) memantine on the plasma corticosterone and eating parameters disturbance induced by acute stress were investigated. Methods. Male Wistar rats (W: 250–300 g) were divided into control and experiential groups, each of which received memantine either intra-VTA or peripherally. One week after bilateral cannulation, the rats received memantine (1 and 5 μg/Rat) five min before electroshock stress. The other experimental groups received memantine (1 and 5 mg/kg) intraperitoneally 30 min before stress. The control groups received saline or memantine but did not experience stress. Food and water intake and plasma corticosterone level were recorded. Results. Results showed that stress decreases food intake but does not change water intake and increase in plasma corticosterone level. Intraperitoneal memantine administration slightly inhibits the stress effects on food intake. However, water intake and plasma corticosterone level were increased. Intra-VTA memantine reduces the effects of stress on corticosterone and water intake. Conclusion. It could be concluded that inhibition of glutamate NMDA receptors in the VTA by memantine leads to the inhibition of the eating behavior parameters and plasma corticosterone level disturbance induced by stress in rats.

SHELL Part of Nucleus Accumbens and Its Laterality Has Important Role in Response to Chronic Stress in Female Rats

“…Howbeit, Anderson reported that transient stress caused animals to received less food pellets by decreasing lever pressing that consequently led to their weight loss; however, after 14 days of stress, both measures returned to pre-stress levels. On the other hand, in other studies, it was shown that foot-shock stress resulted in decreased food intake in male rats [32,33]. In accordance with the current study [34], that was found an increased expression of orexigenic relaxin-3 and misbalanced HPA axis activity raised food intake in condition of chronic stress in female rats [35].Thus, it can be concluded that chronic stress leads to the increment of food intake in female rather than male rats.…”

Memantine Differentially Regulates Tau Phosphorylation Induced by Chronic Restraint Stress of Varying Duration in Mice

“…However, MEM-treated animals had a similar mean body weight to that of stressed animals. These results suggest that different mechanisms may be involved in the control of anxiety and body weight in response to CRS [54].…”

The impact of stress on body function: a review

“…First, stress can affect appetite (Bagheri Nikoo et al, 2014[ 2 ]; Halataei et al, 2011[ 37 ]; Ranjbaran et al, 2013[ 86 ]). This effect is related to involvement of either the ventral tegmental area (VTA), or the amygdala via N-methyl-D-aspartate (NMDA) glutamate receptors (Nasihatkon et al, 2014[ 80 ]; Sadeghi et al, 2015[ 94 ]). However, it should also be noted that nutrition patterns have effects on the response to stress (Ghanbari et al, 2015[ 31 ]), and this suggests a bilateral interaction between nutrition and stress.…”