关键词: 水蛭, 体环, AP神经元, 电突触, 部位分辨, 电导调制

Abstract: This paper revealed that the different strength of synapses on AP neuron can be shown by the mechanical stimulation applied on the skin surface in the neighbouring segment of a ganglion-body wall preparation in the leech Whitmania pigra. The comparisons were made (1) on the effect of receptive neuron evoked by mechanical stimuli in different annuli of the same segment, (2) on the postsynaptic effects of AP neuron evoked by the same mechanical stimuli in different annuli and (3) also in a single annulus of the segment evoked by the same stimuli in different positions. It is established that the synapses of AP neuron function in positional discrimination and integration by synaptic strength.The authors use double voltage clamp in both the pre-synaptic T neuron and the post-synaptic AP neuron in situ showed that the synaptic strength of AP neuron was modulated mainly by the different conductance of its electrical synaptic transmission. The synaptic conductance between T and AP neurons is modulated by the difference of membrane potential between T and AP neurons. By this mechanism electrical synapses of AP neuron can transform the position information of reception into the spatial discrimination of perception.

Key words: leech, annulus, AP neuron, electrical synapse, positional discrimination, conductance modulation