FRIDAY, 18 MARCH 2011The research aimed to test whether motor learning capacity in adults was influenced by variation in levels of an inhibitory neurotransmitter, GABA. Using anodal transcranial direct current stimulation (tDCS) a low level electric current was delivered to the scalps of volunteers. This stimulation is known to cause a decrease in GABA concentration and enhance short-term learning. GABA concentrations in the brain were measured following the stimulation to quantify the individual's baseline level of GABA and their ‘responsiveness’ to the neurotransmitter.
The same individuals were challenged on a separate day with a sequence of learning tasks performed with the ﬁngers of their right hand. The study found that individuals who had a more responsive GABA system were those that demonstrated faster short-term learning and increased learning-related brain activity . Subjects who had higher baseline concentrations of GABA in the primary motor cortex, a region of the brain involved in planning and executing movements, showed slower reaction times in the tasks.
GABA modulation is known to have an important role in learning, and these findings suggest that responsiveness of the GABAergic system may be relevant for development of the neural connections that facilitate learning and memory. The study also provides strong rationale for the use of tDCS as a tool for helping rehabilitation of motor learning in stroke victims, where it is already being implemented to decrease GABA after brain trauma .
Written by Anand Jagatia