An exercise ‘sweet spot’ has been discovered which researchers say reverses cognitive decline in ageing mice, paving the way for human studies in this area.
After more than a decade of research, a Queensland Brain Institute team has found that 35 days of physical exercise improved memory and learning.
“We tested the cognitive ability of elderly mice following defined periods of exercise and found an optimal period or ‘sweet spot’ that greatly improved their spatial learning,” Dr Dan Blackmore said, who led the study alongside Emeritus Professor Perry Bartlett.
The researchers also discovered how exercise improved learning.
“We found that growth hormone (GH) levels peaked during this time, and we’ve been able to demonstrate that artificially raising GH in sedentary mice also was also effective in improving their cognitive skills”, Dr Blackmore said.
“We discovered GH stimulates the production of new neurons in the hippocampus – the region of the brain critically important to learning and memory.
“This is an important discovery for the thousands of people diagnosed with dementia every year.”
Dementia continues to rise globally, with an estimated 55 million people globally living with the condition – a number predicted to grow to 78 million by 2030.
Prof Bartlett said the findings provide further proof that loss of cognitive function in old age is directly related to the diminished production of new neurons.
“It underlines the importance of being able to activate the neurogenic stem cells in the brain that we first identified 20 years ago,” Prof Bartlett said.
The team were able to explore how the production of new neurons changed the circuitry in the brain using Magnetic Resonance Imaging (MRI).
“Using MRI, we were able to study the brain following exercise, and for the first time identify the critical changes in the structure and functional circuitry of the hippocampus required for improved spatial learning,” Dr Blackmore said.
