Startle stimuli exert opposite effects on human cortical and spinal motor system excitability in leg muscles
Standard
Startle stimuli exert opposite effects on human cortical and spinal motor system excitability in leg muscles. / Ilic, T V; Pötter-Nerger, M; Holler, I; Siebner, H R; Ilic, N V; Deuschl, G; Volkmann, J.
In: PHYSIOL RES, Vol. 60 Suppl 1, 2011, p. S101-6.Research output: SCORING: Contribution to journal › SCORING: Journal article › Research › peer-review
Harvard
APA
Vancouver
Bibtex
}
RIS
TY - JOUR
T1 - Startle stimuli exert opposite effects on human cortical and spinal motor system excitability in leg muscles
AU - Ilic, T V
AU - Pötter-Nerger, M
AU - Holler, I
AU - Siebner, H R
AU - Ilic, N V
AU - Deuschl, G
AU - Volkmann, J
PY - 2011
Y1 - 2011
N2 - Increased excitability of the spinal motor system has been observed after loud and unexpected acoustic stimuli (AS) preceding H-reflexes. The paradigm has been proposed as an electrophysiological marker of reticulospinal tract activity in humans. The brainstem reticular formation also maintains dense anatomical interconnections with the cortical motor system. When a startling AS is delivered, prior to transcranial magnetic stimulation (TMS), the AS produces a suppression of motor evoked potential (MEP) amplitude in hand and arm muscles of healthy subjects. Here we analyzed the conditioning effect of a startling AS on MEP amplitude evoked by TMS to the primary motor leg area. Ten healthy volunteers participated in two experiments that used a conditioning-test paradigm. In the first experiment, a startling AS preceded a suprathreshold transcranial test stimulus. The interstimulus interval (ISI) varied between 20 to 160 ms. When given alone, the test stimulus evoked a MEP amplitude of approximately 0.5 mV in the slightly preinervated soleus muscle (SOL). In the second experiment, the startling AS was used to condition the size of the H-reflex in SOL muscle. Mean MEP amplitude was calculated for each ISI. The conditioning AS suppressed MEP amplitude at ISIs of 30-80 ms. By contrast, H-reflex amplitude was augmented at ISIs of 100-200 ms. In conclusions, acoustic stimulation exerts opposite and ISI-specific effects on the amplitude of MEPs and H-reflex in the SOL muscle, indicating different mechanism of auditory-to-motor interactions at cortical and spinal level of motor system.
AB - Increased excitability of the spinal motor system has been observed after loud and unexpected acoustic stimuli (AS) preceding H-reflexes. The paradigm has been proposed as an electrophysiological marker of reticulospinal tract activity in humans. The brainstem reticular formation also maintains dense anatomical interconnections with the cortical motor system. When a startling AS is delivered, prior to transcranial magnetic stimulation (TMS), the AS produces a suppression of motor evoked potential (MEP) amplitude in hand and arm muscles of healthy subjects. Here we analyzed the conditioning effect of a startling AS on MEP amplitude evoked by TMS to the primary motor leg area. Ten healthy volunteers participated in two experiments that used a conditioning-test paradigm. In the first experiment, a startling AS preceded a suprathreshold transcranial test stimulus. The interstimulus interval (ISI) varied between 20 to 160 ms. When given alone, the test stimulus evoked a MEP amplitude of approximately 0.5 mV in the slightly preinervated soleus muscle (SOL). In the second experiment, the startling AS was used to condition the size of the H-reflex in SOL muscle. Mean MEP amplitude was calculated for each ISI. The conditioning AS suppressed MEP amplitude at ISIs of 30-80 ms. By contrast, H-reflex amplitude was augmented at ISIs of 100-200 ms. In conclusions, acoustic stimulation exerts opposite and ISI-specific effects on the amplitude of MEPs and H-reflex in the SOL muscle, indicating different mechanism of auditory-to-motor interactions at cortical and spinal level of motor system.
KW - Acoustic Stimulation
KW - Adult
KW - Analysis of Variance
KW - Cerebral Cortex
KW - Electromyography
KW - Evoked Potentials, Motor
KW - Female
KW - Germany
KW - H-Reflex
KW - Humans
KW - Lower Extremity
KW - Male
KW - Motor Neurons
KW - Muscle, Skeletal
KW - Neural Inhibition
KW - Reflex, Startle
KW - Spinal Nerves
KW - Time Factors
KW - Transcranial Magnetic Stimulation
KW - Journal Article
KW - Randomized Controlled Trial
M3 - SCORING: Journal article
C2 - 21777020
VL - 60 Suppl 1
SP - S101-6
JO - PHYSIOL RES
JF - PHYSIOL RES
SN - 0862-8408
ER -