[Interrelations between sympathetic and parasympathetic inputs into ganglia of the metasympathetic nervous system].

Organization of the sympathetic and parasympathetic inputs into two regions of the metasympathetic ganglia including those of the colon and the urinary bladder, revealed differences between them. The sympathetic outflow evokes inhibitory responses from the smooth muscle walls of common organs and excitatory responses from areas of sphincters. The sacral parasympathetic axons mostly provide excitatory input. The peripheral efferents of the inhibitory reflex are composed of axons passing en route via paravertebral ganglia. A long-latency inhibition follows trains of stimuli owing, probably, to slow inhibitory processes. Purinergic mechanism is involved in the autonomic transmission in the bladder ganglia and based, probably, on the interaction with P1 membrane receptors. Continuous stimulation of parasympathetic axons evokes responses with rising amplitude in the fibers passing to muscles of both organs. After cessation of the stimulation, facilitation of transmission occurs due to presynaptic mechanisms of ACh release. In the bladder ganglia a special mechanism periodically following the "all or nothing" pattern, acts. This input mechanism is capable of both "filtering" low frequencies of the ganglion activity and augmenting the discharges arising during emptying of the organ.