[Some conceptual aspects in studies of the autonomic nervous system].

As a result of intensive research performed in different laboratories recent years in the field of autonomic nervous system physiology, considerable experimental material was collected and some new and interesting hypotheses were proposed. This review is a short sketch about the progress in the study of autonomic transmission mechanisms. Since the sixties of the last century non-adrenergic non-cholinergic nerves were opened, and it was the later recognition of a multiplicity of neurotransmitter substances in autonomic nerves. The concept of cotransmission proposed in the late seventies was found for sympathetic, parasympathetic and enteric nerves. The idea of presynaptic receptors gave impetus to recognition of neuromodulation, and the existence of nonsynaptic interaction between neurons became an obvious fact for the last forty years after its discovery. The article describes the types of synaptic interaction of the autonomic nervous system neurons by the example of sympathetic neurons of the superior cervical ganglion and plasticity of the neurons of this ganglia grown in culture conditions in relation to the expression ofadrenergic and cholinergic properties as well as the role of the calcium ions in regulation of cellular processes. Studies of the last few decades have given impetus for elaboration of new concepts of autonomic nervous system function, part of which is represented in this review. The prospects for further investigations are described.

[Synaptic responses and intraganglionic connections of rat superior cervical ganglia neurons].

The rat superior cervical ganglion (SCG) neurones demonstrate responses on the threshold stimulation of the cervical sympathetic nerve, extrinsic (ECN) and intrinsic (ICN) carotid nerves. Both antidromic and synaptic responses were evoked by antidromic stimulation of ECN and ICN. The synaptic responses of each neuron differ by great variability amplitudes of the excitatory postsynaptic potentials and the currents, the rise time and the time constant decay of the postsynaptic current. We hypothesize that this variability of the synaptic responces is associated with the spatial distribution of synapses on the dendritic tree and on the neuron soma that are innervated by the single axon.

[The pharmacological blockade of the cardiac and gastric enteric ganglia by a new parasympatholytic]. / Farmakolohichna blokada sertsevykh i enteral'nykh hanhliïv shlunka novym parasympatolitykom.

The blocking effects of a newly synthetized compound N-decyltropine bromide (IEM-1556), on pentagastrin-, carbachol- and histamine-induced gastric secretion in chronic dogs, on stress-induced changes in gastric mucosa in rats, on vagus-induced effect in heart and on arterial blood pressure in rats were studied. The effects were compared with those produced by hexamethonium, a conventional ganglionic blocking agent. IEM-1556 inhibited gastric secretion and acid output for a much longer time than hexamethonium did. It also effectively protected gastric mucosa against stress-induced erosions and hemorrhages. IEM-1556 much more effectively blocked the vagus-induced reduction of the heart rate than hexamethonium did, and, in contrast to latter, did not reduce the arterial blood pressure. The results suggest that IEM-1556 is a highly selective blocking agent for parasympathetic and enteric ganglia versus sympathetic ganglia.