Cortical Inhibition State-Dependent iTBS Induced Neural Plasticity

Xiaoying Diao; Qian Lu; Lei Qiao; Youhui Gong; Xiao Lu; Min Feng; Panpan Su; Ying Shen; Ti-Fei Yuan; Chuan He

doi:10.3389/fnins.2022.788538

Cortical Inhibition State-Dependent iTBS Induced Neural Plasticity

Front Neurosci. 2022 Feb 17:16:788538. doi: 10.3389/fnins.2022.788538. eCollection 2022.

Authors

Xiaoying Diao^{1

2}, Qian Lu¹, Lei Qiao³, Youhui Gong¹, Xiao Lu¹, Min Feng¹, Panpan Su¹, Ying Shen⁴, Ti-Fei Yuan^{2

5

6}, Chuan He¹

Affiliations

¹ Department of Rehabilitation Medicine, The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Suzhou, China.
² Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
³ Jiangsu Zhongshan Geriatric Rehabilitation Hospital, Nanjing, China.
⁴ Rehabilitation Medicine Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
⁵ Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China.
⁶ Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China.

Abstract

Background: Intermittent theta burst stimulation (iTBS) is an effective stimulus for long-term potentiation (LTP)-like plasticity. However, iTBS-induced effects varied greatly between individuals. Ample evidence suggested that an initial decrease in local γ-aminobutyric acid (GABA) or enhancement in N-methyl-D-aspartate (NMDA) facilitation neurotransmission is of vital importance for allowing LTP-like plasticity to occur. Therefore, we aimed to investigate whether the individual level of GABA or NMDA receptor-mediated activity before stimulation is correlated with the after-effect in cortical excitability induced by iTBS.

Methods: Fifteen healthy volunteers were recruited for the present study. We measured short-interval intracortical inhibitory (SICI), long-interval intracortical inhibitory (LICI), and intracortical facilitation (ICF), which index GABA_A receptor-, GABA_B receptor-, and glutamate receptor-mediated activity, respectively, in the cortex before conducting iTBS. After iTBS intervention, the changes of motor-evoked potential (MEP) amplitude were taken as a measure for cortical excitability in response to iTBS protocol.

Results: There was a significant negative correlation between the amount of SICI measured before iTBS and the after-effect of iTBS-induced LTP-like plasticity at the time points of 5, 10, and 15 min after inducing iTBS. A multiple linear regression model indicated that SICI was a good predictor of the after-effect in cortical excitability induced by iTBS at 5, 10, and 15 min following stimulation.

Conclusion: The present study found that GABA_A receptor-mediated activity measured before stimulation is negatively correlated with the after-effect of cortical excitability induced by iTBS. SICI, as the index of GABA_A receptor-mediated activity measured before stimulation, might be a good predictor of iTBS-induced LTP-like plasticity for a period lasting 15 min following stimulation.

Keywords: GABAA receptor-mediated activity; GABAB receptor-mediated activity; LTP-like plasticity; N-methyl-D-aspartate receptor-mediated activity; intermittent theta burst stimulation.