[Blood serum of patients with secondary progressive multiple sclerosis changes neuron electric activity]

An effect of 20% blood serum estimated by the changes of background and excited spike activity of Retzius' neuron by Hirudo medicinalis, which does not contain myelin, has been studied in 2 groups of patients. The first group comprised patients with serum, containing antibodies to gangliosides, and the second one--patients without such antibodies. Incubation of Reitzius neurons in the serum with GM1-antibodies within 40 min resulted in the change of spike form, increase of cell stimulation threshold by average 20%, reduction of the frequency of spontaneous impulse activity by average 28%, decrease of the spikes number in response to the lower frequency (0.5 Hz) synaptic stimulation and inhibition of adaptation to the high frequency (10 Hz) stimulation. The use of the serum without GM1-antibodies caused a different change of the spike form and increased the stimulation threshold by 8% and sparser background impulse activity of the neuron by 40%. During low frequency synaptic activation of the neuron (0.5%), there was sensitivity disturbance and inhibition of the electric response to the high frequency stimulation. The results suggest that neuron injuries in multiple sclerosis may develop before morphological appearances of myelin lesions.