A study led by University of Tsukuba researchers say physical activity may improve hippocampal memory dysfunction, with enhanced transport of lactate to neurons likely to be the underlying mechanism
Type 2 diabetes is characterized by impaired glucose metabolism and can cause central nervous system-related complications, such as memory dysfunction, wrote researchers in the journal Diabetologia.
The hippocampus is an essential brain component for normal memory formation. However, the effect of impaired glycometabolism on hippocampal-mediated memory in type 2 diabetes patients is not known.
In a new study, researchers investigated whether hippocampal glucose metabolism and memory function is altered in a rat model of type 2 diabetes.
Based on the idea that exercise normalizes glycometabolism and improves memory function, the research team also investigated the effects of exercise on hippocampal glycometabolism and memory formation.
Hippocampal function was evaluated by placing the rat in a circular pool and testing its ability to remember the location of a platform that would allow it to escape from the water.
“This is a well-established method for measuring spatial learning and memory,” study first author Takeru Shima says.
Type 2 diabetic rats needed more time to escape the water and find the platform. However, after four weeks of moderate exercise, they were able to find the platform much faster.
“This indicated that exercise significantly improved spatial memory impairments in type 2 diabetic rats,” Shima explained.
“We showed for the first time that glycogen levels are significantly higher in the hippocampus of diabetic rats,” corresponding author Hideaki Soya said.
The findings indicate that moderate exercise could be used to treat memory impairment in patients with type 2 diabetes by promoting the transfer of glycogen-derived lactate to hippocampal neurons.
The study concluded: “Our findings are the first to describe detailed profiles of glycometabolism in the type 2 diabetic hippocampus and to show that 4 weeks of moderate exercise improves memory dysfunction in type 2 diabetes via amelioration of dysregulated hippocampal glycometabolism. Dysregulated hippocampal lactate-transport-related glycometabolism is a possible aetiology of type-2-diabetes-mediated memory dysfunction.”
“Moderate exercise ameliorates dysregulated hippocampal glycometabolism and memory function in a rat model of type 2 diabetes”
Author: Takeru Shima, et al.