Abstract
The interaction of the junction potentials in response to ortho- and antidromic hypogastric nerve stimulation in mouse vas deferens was studied, using an extracellular recording method. Ortho-dromic repetitive hypogastric nerve stimulation (10 Hz, 5 min) simultaneously depressed the amplitude of the junction potentials in response to both ortho- and anti-dromic hypogastric nerve stimulation (post-tetanic depression). No time-lag in recovery from the post-tetanic depression was observed between the junction potentials recorded from two separate electrodes, indicating that the proximodistal axonal flow of available transmitter was not involved in the recovery process. Double shocks, with intervals from 10 msec to 1 sec, were applied to the hypogastric nerve. The junction potentials in response to ortho- and ortho-dromic or anti- and anti-dromic double shock were markedly facilitated. On the contrary, the junction potentials in response to ortho- and anti-dromic double shocks were not facilitated. The findings indicate, that facilitation of the junction potentials is produced by the impulses propagated in the same direction along the terminal axon and also that the origin of the facilitation may be at a pre-jtrnctional site.
