Effects of monoaminergic drugs on training-induced motor cortex plasticity in older adults.

Effects of monoaminergic drugs on training-induced motor cortex plasticity in older adults. Brain Res. 2017 Jun 17;: Authors: Kesar TM, Belagaje SR, Pergami P, Haut MW, Hobbs G, Buetefisch CM Abstract Primary motor cortex (M1) plasticity is involved in motor learning and stroke motor recovery, and enhanced by increasing monoaminergic transmission. Age impacts these processes but there is a paucity of systematic studies on the effects of monoaminergic drugs in older adults. Here, in ten older adults (age 61+ 4 years, 4 males), we determine the effects of a single oral dose of carbidopa/levodopa (DOPA), d-amphetamine (AMPH), methylphenidate (MEPH) and placebo (PLAC) on M1 excitability and motor training-induced M1 plasticity. M1 plasticity is defined as training related long lasting changes in M1 excitability and kinematics of the trained movement. At peak plasma level of the drugs, subjects trained wrist extension movements for 30 minutes. Outcome measures were motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation at increasing intensity (stimulus response curve, SRC) and peak acceleration of the trained wrist extension movements. Measures were obtained before and after completion of training. The curve parameters plateau (MEPmax), inflection point, and slope were extracted from SRC. At baseline drugs had a differential effect on curve parameters, while kinematics remained unchanged. Training alone (PLAC) increa...
Source: Brain Research - Category: Neurology Authors: Tags: Brain Res Source Type: research