Cafeína suprime a melhora na memória de longa duração e de localização induzida pelo exercício em ratos de meia-idade

Abstract

The cognitive function decline is closely related with brain changes generated by age. The ability of caffeine and exercise to prevent memory impairment has been reported in animal models and humans. The purpose of the present study was to investigate whether swimming exercise and caffeine administration enhance memory in middle-aged Wistar rats. Male Wistar Rats (18 months) received caffeine at a dose of 30 mg/kg, 5 days per week by a period of 4 weeks. Animals were subjected to swimming training with a workload (3% of body weight, 20 min per day for 4 weeks). After 4 weeks, the object recognition test (ORT) and the object location test (OLT) were performed. After behavioral tests, all animals were killed by decapitation, brains were removed and hippocampi were separated for analysis. The results of this study demonstrated that caffeine suppressed exercise-enhanced long-term (ORT) and spatial (OLT) memory in middle-aged and this effect may be related to a decrease in phosphorylated cAMP-response element-binding protein (p-CREB) hippocampal signaling. This study also provided evidence that the effects of this protocol on memory were not accompanied by alterations in the levels of phosphorylated serine/threonine protein kinase (p-Akt). The [3H] glutamate uptake was reduced in hippocampus of rats administered with caffeine and submitted to swimming protocol. In conclusion, caffeine suppressed the effect of exercise in improving long-term memory, spatial memory, the active and phosphorylated levels of Akt and CREB.