Neuroplasticity - exercise-induced response

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The below may be of interest:

Sports Med. 2010 Sep 1;40(9):765-801. doi: 10.2165/11534530-000000000-00000.

Neuroplasticity - exercise-induced response of peripheral brain-derived

neurotrophic factor: a systematic review of experimental studies in human

subjects.

Knaepen K, Goekint M, Heyman EM, Meeusen R.

Abstract

Exercise is known to induce a cascade of molecular and cellular processes that

support brain plasticity. Brain-derived neurotrophic factor (BDNF) is an

essential neurotrophin that is also intimately connected with central and

peripheral molecular processes of energy metabolism and homeostasis, and could

play a crucial role in these induced mechanisms.

This review provides an overview of the current knowledge on the effects of

acute exercise and/or training on BDNF in healthy subjects and in persons with a

chronic disease or disability. A systematic and critical literature search was

conducted. Articles were considered for inclusion in the review if they were

human studies, assessed peripheral (serum and/or plasma) BDNF and evaluated an

acute exercise or training intervention. Nine RCTs, one randomized trial, five

non-randomized controlled trials, five non-randomized non-controlled trials and

four retrospective observational studies were analysed.

Sixty-nine percent of the studies in healthy subjects and 86% of the studies in

persons with a chronic disease or disability, showed a 'mostly transient'

increase in serum or plasma BDNF concentration following an acute aerobic

exercise. The two studies regarding a single acute strength exercise session

could not show a significant influence on basal BDNF concentration. In studies

regarding the effects of strength or aerobic training on BDNF, a difference

should be made between effects on basal BDNF concentration and training-induced

effects on the BDNF response following an acute exercise. Only three out of ten

studies on aerobic or strength training (i.e. 30%) found a training-induced

increase in basal BDNF concentration. Two out of six studies (i.e. 33%) reported

a significantly higher BDNF response to acute exercise following an aerobic or

strength training programme (i.e. compared with the BDNF response to an acute

exercise at baseline). A few studies of low quality (i.e. retrospective

observational studies) show that untrained or moderately trained healthy

subjects have higher basal BDNF concentrations than highly trained subjects.

Yet, strong evidence still has to come from good methodological studies.

Available results suggest that acute aerobic, but not strength exercise

increases basal peripheral BDNF concentrations, although the effect is

transient. From a few studies we learn that circulating BDNF originates both

from central and peripheral sources. We can only speculate which central regions

and peripheral sources in particular circulating BDNF originates from, where it

is transported to and to what purpose it is used and/or stored at its final

destination. No study could show a long-lasting BDNF response to acute exercise

or training (i.e. permanently increased basal peripheral BDNF concentration) in

healthy subjects or persons with a chronic disease or disability.

It seems that exercise and/or training temporarily elevate basal BDNF and

possibly upregulate cellular processing of BDNF (i.e. synthesis, release,

absorption and degradation). From that point of view, exercise and/or training

would result in a higher BDNF synthesis following an acute exercise bout (i.e.

compared with untrained subjects). Subsequently, more BDNF could be released

into the blood circulation which may, in turn, be absorbed more efficiently by

central and/or peripheral tissues where it could induce a cascade of

neurotrophic and neuroprotective effects.

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Carruthers

Wakefield, UK