OBJECTIVE: To investigate the functional organization of inhibitory spinal reflexes mediated by cutaneous afferents (=cutaneous silent periods, CSPs) in order to assess differential strategies used by the @entity1 spinal cord to inhibit movement in upper limb muscles within the same myotome. METHODS: Twenty healthy subjects underwent assessment of the effect of electrical finger-tip stimulation with different intensities on voluntarily contracting hand muscles. The rectified and averaged electromyogram (EMG) was recorded with surface electrodes placed over abductor pollicis brevis (APB), @entity8807 ( @entity8807 ), and first dorsal interosseous (FDI) muscles following recurrent digit II and digit V stimulation. RESULTS: Finger-tip stimulation resulted in a series of inhibitory and excitatory EMG responses in all 3 hand muscles. Stimulus intensity exerted a significant influence on various CSP parameters (probability, onset and end latency, duration, index of @entity1155 ). CSPs were most pronounced in APB following digit II and, somewhat less, following digit V stimulation. FDI and @entity8807 differed in CSP onset latency following digit II stimulation, and in the overall amount of @entity1155 following digit V stimulation, despite being supplied by the same nerve and the same myotome. Excitatory long-loop reflexes seemed to be suppressed by increasing stimulus intensities, yet they interfered with CSPs, even when using noxious stimulation, in FDI following digit II stimulation, and in both @entity8807 and FDI following digit V stimulation. CONCLUSIONS: The findings are consistent with the presence of an inhibitory neural circuitry within the @entity1 spinal cord which can rapidly restrain distinct @entity121 . Neurophysiology indicates a more functional - task-related - organization of protective reflexes in the @entity1 upper extremity, rather than a merely metameric - anatomically based - order of activation of this neuronal circuitry.

Functional organization of exteroceptive inhibition following nociceptive electrical fingertip stimulation in XXXX .

@entity1 :: ('9606', 'Species') :: ['human'] @entity121 :: ('MESH:D009135', 'Disease') :: ['muscle synergies'] @entity8807 :: ('MESH:C536354', 'Disease') :: ['abductor digiti minimi', 'ADM'] @entity1155 :: ('MESH:D011596', 'Disease') :: ['suppression']
@entity1 :: (9606,Species) :: ['humans']
