Central-peripheral plasticity in sensory impulse conduction

点击翻译按钮获取中文摘要

1.Electrophysiological changes in asymptomatic peripheral neuropathy.We performed electrophysiological changes in diabetic patients with asymptomatic polyneuropathy, which was defined as no neuropathic symptom and loss of ankle jerk. We found two or more abnormalities of nerve conduction parameter m 81 percent of the patients Central conduction time was delayed in some patients, indicating degenerating procedd of the nerve fibers even in asymptomatic neuropathy.2.Origin of high frequency oscillation(HFO) in the somatosensory cortex.The dipole orientation of equivalent current source for HFOs above 300Hz and that for the underlying N20m were compared. We found that the orientation of of the HFOs and underlying 20m current source differs and that HFO source orientation shows more divergent pattern than the 20m. The results suggest hat they may reflect activities of the non-pyramidal neuron population.3.Activation of isofrequency bands through horizontal fibers in auditory cortex.Early cognitive process in the primary auditory cortex were studied by measuring auditory evoked magnetic fields(AEF) during selective attention tasks. N100 dipole strength for 400Hz and 4000Hz stimuli was enlarged in both pitch and laterality discrimination tasks. The dipole distance between 400Hz and 4000Hz tones was larger during pitch discrimination task but unchanged during laterally discrimination task. We speculate that these dynamic changes in the N100m dipole reflect short-term plasticity in auditory cortex.