Tonic neuronal activation during simple and complex finger movements analyzed by DC-magnetoencephalography

• Published in: Neuroscience letters 2006-02, Vol.394 (1), p.42-47
• Main Authors: Leistner, Stefanie, Wuebbeler, Gerd, Trahms, Lutz, Curio, Gabriel, Mackert, Bruno-Marcel
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Brain Mapping; Direct current; Evoked Potentials, Somatosensory - physiology; Evoked Potentials, Somatosensory - radiation effects; Female; Finger movement; Fingers - physiology; Functional Laterality - physiology; Fundamental and applied biological sciences. Psychology; Humans; Magnetoencephalography; Male; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Motor cortex; Motor Cortex - physiology; Motor Cortex - radiation effects; Movement - physiology; Movement - radiation effects; Neuronal activation; Psychomotor Performance - physiology; Psychomotor Performance - radiation effects; Vertebrates: nervous system and sense organs
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2005.10.004

Functional neuroimaging techniques map neuronal activation indirectly via local concomitant cortical vascular/metabolic changes. In a complementary approach, DC-magnetoencephalography measures neuronal activation dynamics directly, notably in a time range of the slow vascular/metabolic response. Here, using this technique neuronal activation dynamics and patterns for simple and complex finger movements are characterized intraindividually: in 6/6 right-handed subjects contralateral prolonged (30 s each) complex self-paced sequential finger movements revealed stronger field amplitudes over the pericentral sensorimotor cortex than simple movements. A consistent lateralization for contralateral versus ipsilateral finger movements was not found (4/6). A subsequent sensory paradigm focused on somatosensory afferences during the motor tasks and the reliability of the measuring technique. In all six subjects stable sustained neuronal activation during electrical median nerve stimulation was recorded. These neuronal quasi-tonic activation characteristics provide a new non-invasive neurophysiological measure to interpret signals mapped by functional neuroimaging techniques.