The Effects of Exercise on Synaptic Plasticity in Individuals With Mild Cognitive Impairment: Protocol for a Pilot Intervention Study (Preprint)

Abstract

BACKGROUND Mild cognitive impairment (MCI) is a syndrome before more severe impairment characterized by dementia. MCI affects an estimated 15% to 20% of people over age 65. Non-pharmacological interventions including exercise are recommended as part of overall MCI management based on the positive effects of exercise on cognitive performance. Interval training involves brief intermittent bouts of exercise interspersed with short recovery periods. This type of exercise promotes cognitive improvement and can be performed in individuals with MCI. Synaptic plasticity can be assessed in-vivo by the neurophysiological response to repetitive transcranial magnetic stimulation. It is unknown whether interval training causes changes in synaptic plasticity in individuals living with MCI. OBJECTIVE This research will determine whether interval training performed using a cycle ergometer enhances synaptic plasticity in older individuals with MCI. The two aims are: (1) to quantify synaptic plasticity after interval training performed at a self-selected intensity in aging and in individuals with MCI, and (2) to determine whether changes in synaptic plasticity correlate with changes in serum brain-derived neurotrophic factor, osteocalcin, and cognition. METHODS Thirty-six individuals will be recruited for assignment to one of three equally sized groups: exercise in MCI, no exercise in MCI and exercise non-MCI. The Exercise MCI group and the exercise non-MCI will perform thrice weekly exercise sessions for four weeks. Synaptic plasticity will be measured before the exercise intervention and following the four-week intervention. At these time points, synaptic plasticity will be measured as the response to single pulse TMS. before and after an rTMS protocol used to induce synaptic plasticity. RESULTS The study began as of March 2023. CONCLUSIONS The proposed research is the first to assess whether synaptic plasticity is enhanced after exercise training in individuals with MCI. If exercise does, indeed, modify synaptic plasticity, this will create a new avenue by which we can study and manipulate the neural plasticity in these individuals. CLINICALTRIAL clinicaltrials.gov Trial number: NCT05663918