Original ResearchClinical—Alimentary TractVal66Met in Brain-Derived Neurotrophic Factor Affects Stimulus-Induced Plasticity in the Human Pharyngeal Motor Cortex
Section snippets
Participants
Healthy volunteers for this study came from two sources, volunteers from the Dyne-Steele cohort with predetermined BDNF genotype24 and healthy volunteers who responded to the study advertisement. The former group were healthy older volunteers who were part of an ongoing cognitive genetic study undertaken by the University of Manchester, and were invited to take part in this study if they had normal swallowing function as per a validated swallowing questionnaire.25 Subjects from the latter group
Results
Age and sex distribution, baseline recordings for stimulation intensity of single-pulse TMS and MEP for both Val/Val and non-Val/Val subjects for the 3 experiments are shown in Table 1. In our study population, given the low prevalence of the Met66Met genotype, all non-Val/Val subjects were Val66Met heterozygotes.
Discussion
This study aimed to define the influence of the BDNFVal66Met polymorphism on functional flexibility/plasticity in the intact human pharyngeal motor cortex. Pharyngeal motor cortex was stimulated by transcranial magnetic stimulation that excited a polysynaptic descending pathway or pathways that activated motor neurons in the nucleus ambiguus leading to the recruitment of motor units in the pharyngeal muscles. The findings of this study suggest that the pharyngeal motor cortex's response to
Conclusions
We have shown that a common polymorphism of BDNF can exert contrasting effects on neurophysiological outcomes in experimentally induced plasticity paradigms in the intact human pharyngeal motor cortex with the implication that genotype profiling may improve bespoke rehabilitative tools for individual patients.
Acknowledgments
The authors would like to thank staff in CIGMR and the volunteers from the Dyne-Steele cohort.
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Conflicts of interest The authors disclose no conflicts.
Funding Grant support received from the Action Medical Research (Reference: A/P/1091); Biotechnology and Biological Sciences Research Council (BBSRC) (Reference BB.F02244101.1). The study was sponsored by the University of Manchester, UK, which did not have a role in the study design, in the collection, analysis, or interpretation of data.