S. Karunanithi et al., STATISTICS OF QUANTAL SECRETION DURING LONG TRAINS OF SYMPATHETIC-NERVE IMPULSES IN MOUSE VAS-DEFERENS, Journal of physiology, 489(1), 1995, pp. 171-181
1. A statistical analysis has been made of the occurrence of excitator
y junctional currents (EJCs) of similar amplitude recorded with an ext
racellular electrode during long trains of nerve impulses to the mouse
vas deferens. 2. The number of EJCs of similar amplitude that occurre
d in consecutive impulses during trains of 500-1000 impulses at 0.5-2.
0 Hz increased with the number of EJCs evoked during the train. 3. The
re was no evidence of significant dependence between consecutive EJCs
of similar amplitude in sixteen out of eighteen trains in eighteen pre
parations.4. The time course of clusters of EJCs of similar amplitude
was examined by determining the standard deviation of different groups
of EJCs within a cluster throughout their time course. Most EJCs with
in a cluster could be grouped with a coefficient of variation <0.1 thr
oughout their time course. 5. The observations on EJCs of similar ampl
itude leave open the possibility that secretion from single varicositi
es is, in general, multiquantal.