Limits...
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.

Show MeSH

Related in: MedlinePlus

Effect of preconditioning on the after-effects of iTBS: (A) MEPbi amplitude independent of polymorphism, (B) MEPbi amplitude divided by polymorphism, (C) MEPmo amplitude independent of polymorphism, (D) MEPmo amplitude divided by polymorphism.Asterisks indicate significant changes from baseline in the expected direction as revealed by one-sided one-sample t-tests (#P<0.05, *P<0.01, **P<0.001, ***P<0.0001, ****P<0.00001, *****P<0.000001, ******P<0.0000001; please note that p-values indicated by one or more asterisks are also significant when applying two-sided t-tests). Actual p-values are given for post-hoc two-sided paired t-tests comparing different conditions.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3585283&req=5

pone-0057957-g003: Effect of preconditioning on the after-effects of iTBS: (A) MEPbi amplitude independent of polymorphism, (B) MEPbi amplitude divided by polymorphism, (C) MEPmo amplitude independent of polymorphism, (D) MEPmo amplitude divided by polymorphism.Asterisks indicate significant changes from baseline in the expected direction as revealed by one-sided one-sample t-tests (#P<0.05, *P<0.01, **P<0.001, ***P<0.0001, ****P<0.00001, *****P<0.000001, ******P<0.0000001; please note that p-values indicated by one or more asterisks are also significant when applying two-sided t-tests). Actual p-values are given for post-hoc two-sided paired t-tests comparing different conditions.

Mentions: Figure 3 displays the effects of iTBS as percent of the respective immediate pre-iTBS baseline (note that all statistics in this section also rely on these percent values). The after-effects of iTBS strongly depended on preconditioning. One-sample t-tests confirmed the principal facilitation of corticospinal excitability after iTBS. When iTBS was preconditioned with cTBS (iTBScTBS), both MEPbi (5 min: T28 = 5.13, P<0.00001; 25 min: T28 = 7.44, P<0.0000001) and MEPmo (10 min: T28 = 6.30, P<0.000001) were markedly facilitated. The same held true for unconditioned iTBS (iTBSnoTBS): MEPbi (5 min: T27 = 3.42, P = 0.001; 25 min: T27 = 3.97, P<0.001) and MEPmo (10 min: T27 = 6.10, P<0.000001). However, when iTBS was preconditioned with iTBS (iTBSiTBS), facilitation was less strong for both MEPbi (5 min: T27 = 1.59, P = 0.062; 25 min: T27 = 2.00, P = 0.027) and MEPmo (10 min: T27 = 1.49, P = 0.073).


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)

Effect of preconditioning on the after-effects of iTBS: (A) MEPbi amplitude independent of polymorphism, (B) MEPbi amplitude divided by polymorphism, (C) MEPmo amplitude independent of polymorphism, (D) MEPmo amplitude divided by polymorphism.Asterisks indicate significant changes from baseline in the expected direction as revealed by one-sided one-sample t-tests (#P<0.05, *P<0.01, **P<0.001, ***P<0.0001, ****P<0.00001, *****P<0.000001, ******P<0.0000001; please note that p-values indicated by one or more asterisks are also significant when applying two-sided t-tests). Actual p-values are given for post-hoc two-sided paired t-tests comparing different conditions.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0057957-g003: Effect of preconditioning on the after-effects of iTBS: (A) MEPbi amplitude independent of polymorphism, (B) MEPbi amplitude divided by polymorphism, (C) MEPmo amplitude independent of polymorphism, (D) MEPmo amplitude divided by polymorphism.Asterisks indicate significant changes from baseline in the expected direction as revealed by one-sided one-sample t-tests (#P<0.05, *P<0.01, **P<0.001, ***P<0.0001, ****P<0.00001, *****P<0.000001, ******P<0.0000001; please note that p-values indicated by one or more asterisks are also significant when applying two-sided t-tests). Actual p-values are given for post-hoc two-sided paired t-tests comparing different conditions.
Mentions: Figure 3 displays the effects of iTBS as percent of the respective immediate pre-iTBS baseline (note that all statistics in this section also rely on these percent values). The after-effects of iTBS strongly depended on preconditioning. One-sample t-tests confirmed the principal facilitation of corticospinal excitability after iTBS. When iTBS was preconditioned with cTBS (iTBScTBS), both MEPbi (5 min: T28 = 5.13, P<0.00001; 25 min: T28 = 7.44, P<0.0000001) and MEPmo (10 min: T28 = 6.30, P<0.000001) were markedly facilitated. The same held true for unconditioned iTBS (iTBSnoTBS): MEPbi (5 min: T27 = 3.42, P = 0.001; 25 min: T27 = 3.97, P<0.001) and MEPmo (10 min: T27 = 6.10, P<0.000001). However, when iTBS was preconditioned with iTBS (iTBSiTBS), facilitation was less strong for both MEPbi (5 min: T27 = 1.59, P = 0.062; 25 min: T27 = 2.00, P = 0.027) and MEPmo (10 min: T27 = 1.49, P = 0.073).

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