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Brain-derived neurotrophic factor--a major player in stimulation-induced homeostatic metaplasticity of human motor cortex?

Mastroeni C, Bergmann TO, Rizzo V, Ritter C, Klein C, Pohlmann I, Brueggemann N, Quartarone A, Siebner HR - PLoS ONE (2013)

Bottom Line: The plasticity-inducing effects of rTMS in M1HAND show substantial inter-individual variability which has been partially attributed to the val(66)met polymorphism in the brain-derived neurotrophic factor (BDNF) gene.Critically, val(66)met carriers and val(66)val carriers showed very similar response patterns to cTBS and iTBS regardless of the order of TBS interventions.Since none of the observed TBS effects was modulated by the BDNF val(66)met polymorphism, our results do not support the notion that the BDNF val(66)met genotype is a major player with regard to TBS-induced plasticity and metaplasticity in the human M1HAND.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Christian-Albrechts-University, Kiel, Germany.

ABSTRACT
Repetitive transcranial magnetic stimulation (rTMS) of the human motor hand area (M1HAND) can induce lasting changes in corticospinal excitability as indexed by a change in amplitude of the motor-evoked potential. The plasticity-inducing effects of rTMS in M1HAND show substantial inter-individual variability which has been partially attributed to the val(66)met polymorphism in the brain-derived neurotrophic factor (BDNF) gene. Here we used theta burst stimulation (TBS) to examine whether the BDNF val(66)met genotype can be used to predict the expression of TBS-induced homeostatic metaplasticity in human M1HAND. TBS is a patterned rTMS protocol with intermittent TBS (iTBS) usually inducing a lasting increase and continuous TBS (cTBS) a lasting decrease in corticospinal excitability. In three separate sessions, healthy val(66)met (n = 12) and val(66)val (n = 17) carriers received neuronavigated cTBS followed by cTBS (n = 27), cTBS followed by iTBS (n = 29), and iTBS followed by iTBS (n = 28). Participants and examiner were blinded to the genotype at the time of examination. As expected, the first TBS intervention induced a decrease (cTBS) and increase (iTBS) in corticospinal excitability, respectively, at the same time priming the after effects caused by the second TBS intervention in a homeostatic fashion. Critically, val(66)met carriers and val(66)val carriers showed very similar response patterns to cTBS and iTBS regardless of the order of TBS interventions. Since none of the observed TBS effects was modulated by the BDNF val(66)met polymorphism, our results do not support the notion that the BDNF val(66)met genotype is a major player with regard to TBS-induced plasticity and metaplasticity in the human M1HAND.

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Time line of an experimental session.The experiment consisted of three of these sessions in each of which two different TBS protocols were subsequently applied: iTBS followed by iTBS (i-iTBS), cTBS followed by iTBS (c-iTBS), and cTBS followed by cTBS (c-cTBS).Motor evoked potentials (MEPs) were recorded at the contralateral FDI muscle both with biphasic pulses (MEPbi) at baseline as well as 5 and 25 minutes after the end of each TBS intervention and with monophasic pulses (MEPmo) at baseline, and 10 min after the end of each TBS intervention. Session were randomized in order across subjects and were conducted at least five days apart.
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pone-0057957-g001: Time line of an experimental session.The experiment consisted of three of these sessions in each of which two different TBS protocols were subsequently applied: iTBS followed by iTBS (i-iTBS), cTBS followed by iTBS (c-iTBS), and cTBS followed by cTBS (c-cTBS).Motor evoked potentials (MEPs) were recorded at the contralateral FDI muscle both with biphasic pulses (MEPbi) at baseline as well as 5 and 25 minutes after the end of each TBS intervention and with monophasic pulses (MEPmo) at baseline, and 10 min after the end of each TBS intervention. Session were randomized in order across subjects and were conducted at least five days apart.

Mentions: The TMS experiments consisted of three separate sessions performed at least five days apart to minimize carry-over effects (Fig. 1). All experiments were performed during day time (10∶00 am–7∶00 pm) hours. In each session, subjects received two TBS interventions to the left M1HAND which were separated by an interval of ∼30 minutes. Apart from two subjects, all participants received three different combinations of TBS (Fig. 1): (i) cTBS followed by cTBS (c-cTBS), (ii) iTBS followed by iTBS (i-iTBS), and (iii) cTBS followed by iTBS (c-iTBS). The order of TBS-TBS interventions was pseudorandomized across subjects. One subject only participated in the c-iTBS session and another subject only in the c-iTBS and i-iTBS session. At the beginning of the first session, a blood sample was taken for BDNF genotyping.


Brain-derived neurotrophic factor--a major player in stimulation-induced homeostatic metaplasticity of human motor cortex?

Mastroeni C, Bergmann TO, Rizzo V, Ritter C, Klein C, Pohlmann I, Brueggemann N, Quartarone A, Siebner HR - PLoS ONE (2013)

Time line of an experimental session.The experiment consisted of three of these sessions in each of which two different TBS protocols were subsequently applied: iTBS followed by iTBS (i-iTBS), cTBS followed by iTBS (c-iTBS), and cTBS followed by cTBS (c-cTBS).Motor evoked potentials (MEPs) were recorded at the contralateral FDI muscle both with biphasic pulses (MEPbi) at baseline as well as 5 and 25 minutes after the end of each TBS intervention and with monophasic pulses (MEPmo) at baseline, and 10 min after the end of each TBS intervention. Session were randomized in order across subjects and were conducted at least five days apart.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3585283&req=5

pone-0057957-g001: Time line of an experimental session.The experiment consisted of three of these sessions in each of which two different TBS protocols were subsequently applied: iTBS followed by iTBS (i-iTBS), cTBS followed by iTBS (c-iTBS), and cTBS followed by cTBS (c-cTBS).Motor evoked potentials (MEPs) were recorded at the contralateral FDI muscle both with biphasic pulses (MEPbi) at baseline as well as 5 and 25 minutes after the end of each TBS intervention and with monophasic pulses (MEPmo) at baseline, and 10 min after the end of each TBS intervention. Session were randomized in order across subjects and were conducted at least five days apart.
Mentions: The TMS experiments consisted of three separate sessions performed at least five days apart to minimize carry-over effects (Fig. 1). All experiments were performed during day time (10∶00 am–7∶00 pm) hours. In each session, subjects received two TBS interventions to the left M1HAND which were separated by an interval of ∼30 minutes. Apart from two subjects, all participants received three different combinations of TBS (Fig. 1): (i) cTBS followed by cTBS (c-cTBS), (ii) iTBS followed by iTBS (i-iTBS), and (iii) cTBS followed by iTBS (c-iTBS). The order of TBS-TBS interventions was pseudorandomized across subjects. One subject only participated in the c-iTBS session and another subject only in the c-iTBS and i-iTBS session. At the beginning of the first session, a blood sample was taken for BDNF genotyping.

Bottom Line: The plasticity-inducing effects of rTMS in M1HAND show substantial inter-individual variability which has been partially attributed to the val(66)met polymorphism in the brain-derived neurotrophic factor (BDNF) gene.Critically, val(66)met carriers and val(66)val carriers showed very similar response patterns to cTBS and iTBS regardless of the order of TBS interventions.Since none of the observed TBS effects was modulated by the BDNF val(66)met polymorphism, our results do not support the notion that the BDNF val(66)met genotype is a major player with regard to TBS-induced plasticity and metaplasticity in the human M1HAND.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Christian-Albrechts-University, Kiel, Germany.

ABSTRACT
Repetitive transcranial magnetic stimulation (rTMS) of the human motor hand area (M1HAND) can induce lasting changes in corticospinal excitability as indexed by a change in amplitude of the motor-evoked potential. The plasticity-inducing effects of rTMS in M1HAND show substantial inter-individual variability which has been partially attributed to the val(66)met polymorphism in the brain-derived neurotrophic factor (BDNF) gene. Here we used theta burst stimulation (TBS) to examine whether the BDNF val(66)met genotype can be used to predict the expression of TBS-induced homeostatic metaplasticity in human M1HAND. TBS is a patterned rTMS protocol with intermittent TBS (iTBS) usually inducing a lasting increase and continuous TBS (cTBS) a lasting decrease in corticospinal excitability. In three separate sessions, healthy val(66)met (n = 12) and val(66)val (n = 17) carriers received neuronavigated cTBS followed by cTBS (n = 27), cTBS followed by iTBS (n = 29), and iTBS followed by iTBS (n = 28). Participants and examiner were blinded to the genotype at the time of examination. As expected, the first TBS intervention induced a decrease (cTBS) and increase (iTBS) in corticospinal excitability, respectively, at the same time priming the after effects caused by the second TBS intervention in a homeostatic fashion. Critically, val(66)met carriers and val(66)val carriers showed very similar response patterns to cTBS and iTBS regardless of the order of TBS interventions. Since none of the observed TBS effects was modulated by the BDNF val(66)met polymorphism, our results do not support the notion that the BDNF val(66)met genotype is a major player with regard to TBS-induced plasticity and metaplasticity in the human M1HAND.

Show MeSH
Related in: MedlinePlus