Yuyu Song , Jialiang Chen , Xue Xia , Zhen Wang , Jianing Wei , Meilin Song , Jian Zhang
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引用次数: 0
Abstract
Objective
Chronic smoking is associated with differences in intracortical circuits within the hand area of the primary motor cortex. However, given that smoking involves fine hand-to-mouth coordination, its potential impact on the excitability of the oral motor cortex remains unexplored. This study compared people who smoke chronically with those who do not, to examine differences in motor cortex excitability.
Methods
Paired-pulse transcranial magnetic stimulation (TMS) was used to quantify intracortical circuit excitability in the hand and oral motor areas. Single-pulse TMS assessed corticospinal and corticobulbar excitability. Generalized linear mixed models (GLMMs) were applied for statistical analysis, and correlation analyses were conducted to explore associations between electrophysiological measures and smoking-related parameters.
Results
Compared with people who do not smoke, people who smoke showed greater short-interval intracortical inhibition (SICI) in both the hand (5 ms) and oral (3 ms, 5 ms) motor cortices, and reduced intracortical facilitation (ICF) in the hand area (10 ms). Corticospinal excitability did not differ between groups, whereas corticobulbar excitability was lower in people who smoke at higher stimulation intensities.
Conclusion
Chronic smoking is associated with widespread inhibitory plasticity in motor cortical circuits, as indicated by multi-muscle motor-evoked potential (MEP) recordings.
Significance
These findings contribute to understanding of inhibitory circuit function and descending pathway excitability differences linked to chronic nicotine exposure.
期刊介绍:
Drug and Alcohol Dependence is an international journal devoted to publishing original research, scholarly reviews, commentaries, and policy analyses in the area of drug, alcohol and tobacco use and dependence. Articles range from studies of the chemistry of substances of abuse, their actions at molecular and cellular sites, in vitro and in vivo investigations of their biochemical, pharmacological and behavioural actions, laboratory-based and clinical research in humans, substance abuse treatment and prevention research, and studies employing methods from epidemiology, sociology, and economics.