TY - JOUR
T1 - Boosting the LTP-like plasticity effect of intermittent theta-burst stimulation using gamma transcranial alternating current stimulation
AU - Guerra, Andrea
AU - Suppa, Antonio
AU - Bologna, Matteo
AU - D'Onofrio, Valentina
AU - Bianchini, Edoardo
AU - Brown, Peter
AU - Di Lazzaro, Vincenzo
AU - Berardelli, Alfredo
PY - 2018/7/1
Y1 - 2018/7/1
N2 - Background: Transcranial Alternating Current Stimulation (tACS) consists in delivering electric current to the brain using an oscillatory pattern that may entrain the rhythmic activity of cortical neurons. When delivered at gamma frequency, tACS modulates motor performance and GABA-A-ergic interneuron activity. Objective: Since interneuronal discharges play a crucial role in brain plasticity phenomena, here we co-stimulated the primary motor cortex (M1) in healthy subjects by means of tACS during intermittent theta-burst stimulation (iTBS), a transcranial magnetic stimulation paradigm known to induce long-term potentiation (LTP)-like plasticity. Methods: We measured and compared motor evoked potentials before and after gamma, beta and sham tACS-iTBS. While we delivered gamma-tACS, we also measured short-interval intracortical inhibition (SICI) to detect any changes in GABA-A-ergic neurotransmission. Results: Gamma, but not beta and sham tACS, significantly boosted and prolonged the iTBS-induced after-effects. Interestingly, the extent of the gamma tACS-iTBS after-effects correlated directly with SICI changes. Conclusions: Overall, our findings point to a link between gamma oscillations, interneuronal GABA-A-ergic activity and LTP-like plasticity in the human M1. Gamma tACS-iTBS co-stimulation might represent a new strategy to enhance and prolong responses to plasticity-inducing protocols, thereby lending itself to future applications in the neurorehabilitation setting.
AB - Background: Transcranial Alternating Current Stimulation (tACS) consists in delivering electric current to the brain using an oscillatory pattern that may entrain the rhythmic activity of cortical neurons. When delivered at gamma frequency, tACS modulates motor performance and GABA-A-ergic interneuron activity. Objective: Since interneuronal discharges play a crucial role in brain plasticity phenomena, here we co-stimulated the primary motor cortex (M1) in healthy subjects by means of tACS during intermittent theta-burst stimulation (iTBS), a transcranial magnetic stimulation paradigm known to induce long-term potentiation (LTP)-like plasticity. Methods: We measured and compared motor evoked potentials before and after gamma, beta and sham tACS-iTBS. While we delivered gamma-tACS, we also measured short-interval intracortical inhibition (SICI) to detect any changes in GABA-A-ergic neurotransmission. Results: Gamma, but not beta and sham tACS, significantly boosted and prolonged the iTBS-induced after-effects. Interestingly, the extent of the gamma tACS-iTBS after-effects correlated directly with SICI changes. Conclusions: Overall, our findings point to a link between gamma oscillations, interneuronal GABA-A-ergic activity and LTP-like plasticity in the human M1. Gamma tACS-iTBS co-stimulation might represent a new strategy to enhance and prolong responses to plasticity-inducing protocols, thereby lending itself to future applications in the neurorehabilitation setting.
KW - GABA-A
KW - Gamma
KW - Interneurons
KW - Plasticity
KW - tACS
KW - TMS
UR - http://www.scopus.com/inward/record.url?scp=85044592818&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85044592818&partnerID=8YFLogxK
U2 - 10.1016/j.brs.2018.03.015
DO - 10.1016/j.brs.2018.03.015
M3 - Article
C2 - 29615367
AN - SCOPUS:85044592818
VL - 11
SP - 734
EP - 742
JO - Brain Stimulation
JF - Brain Stimulation
SN - 1935-861X
IS - 4
ER -