Startle stimuli exert opposite effects on human cortical and spinal motor system excitability in leg muscles

Title:

Startle stimuli exert opposite effects on human cortical and spinal motor system excitability in leg muscles

Creator:

Ilic, T. V., Pötter-Nerger, M., Holler, I., Siebner, H. R., Ilic, N. V., Günther Deuschl, and Johannes Volkmann

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:6179f232-2bfc-4548-8188-bafce8ddd033
uuid:6179f232-2bfc-4548-8188-bafce8ddd033

Subject:

Fyziologie člověka a srovnávací fyziologie, transkraniální magnetická stimulace, transcranial magnetic stimulation, startling acoustic stimulus, H-reflex, motor cortex, 14, and 612

Type:

article, články, model:article, and TEXT

Format:

print

Description:

Increased excitability of the spinal motor system has been observed after loud and unexpe cted 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 wi th 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) amplitud e 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 seco nd experiment, the startling AS was used to condition the size of the H-reflex in SOL muscle. Mean MEP amplitude was calc ulated 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., T: V. Ilic ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 2011 Volume:60 | Number:Suppl 1

Harvested from:

CDK

Metadata only:

false