Abstract: | Experiments on the myenteric plexus of isolated strips of the small and large intestines showed the presence of adrenosensitive cells capable of responding to application of different concentrations of adrenalin (A) and noradrenalin (NA) by a distinct increase in firing rate. The greatest effect was obtained with NA; the range of action of which was wider (from 10–9 to 10–5 g/ml) than that of A. Addition of phentolamine to the surrounding solution in most cases prevented the appearance of these effects. Besides spontaneously discharging cells, silent neurons with no spontaneous activity also responded to the addition of A and NA. It is suggested that catecholamines may play a direct part in the modulation of processes carried out by neurons in the ganglia of the myenteric plexus.Laboratory of Physiology of the Autonomic Nervous System, I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. (Presented by Academician V. N. Chernigovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 259–261, March, 1977. |