Different Mechanism of Transmission Efficiency in Unmyelinated Nerve Fiber Primary Afferent Synapses

Generally,the bursting firing pattern of action potential has higher transmission efficiency compared with the consecutive firing pattern in the same average frequency condition.Recently,some articles about the synapse short-term plasticity have shown that there are different mechanism to form short-term plasticity in different presynaptic firing frequency condition probably.This makes us to question whether there are different transmission efficiency between presynaptic bursting firing pattern and consecutive firing pattern in different frequency. To answer the questions above, a biophysical mode lof synaptic transmission were constructed.Thesimulative data and the experimental data were compared by employed the coefficient of variation (CV) and mutual information (MI) as indexes,The analysis result indicated that there were different transmission efficiency between presynaptic bursting firing pattern and consecutive firing pattern in different frequency condition. Moreover, we speculate that there are different decisive mechanism of synaptic transmission in different presynaptic firing frequency condition.We speculate that the consecutive firng pattern has higher transmission efficiency when the average frequency is below the 4Hz , which is due to the deactiving of the N-methyl-D-aspartate(NMDA) receptor, the bursting firng pattern has higher transmission efficiency when the average frequency is above the 10Hz , which is due to the co-activing of the a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and NMDA receptors.