Primary Culture of Dissociated Cells of the Rat Retina under Conditions of Long-Lasting Culturing: Properties of Ganglion Cells

We developed a technique for long-lasting culturing of dissociated cells of the rat retina. Electrophysiological characteristics of cultured retinal ganglion cells were examined using a patch-clamp technique in the whole-cell configuration (current-clamp mode). Morphological and electrophysiological characteristics of cultured retinal ganglion cells corresponded to those obtained under conditions of an acute experiment on the cells of similar-age animals; this is indicative of the possibility of using cultured retinal cells in electrophysiological and pharmacological studies.     

Electrophysiological Properties of Cultured Sympathetic Neurons of the Rat Superior Cervical Ganglion

We obtained a viable culture of sympathetic neurons of the superior cervical ganglion of neonatal rats. Electrophysiological experiments (patch-clamp in the whole-cell configuration) showed that the cultured neurons generated action potentials after intercellular stimulation by long-lasting pulses of depolarizing current. In some neurons, background impulse electrical activity and evoked postsynaptic currents suppressed by applications of benzohexonium were observed.     

Selective pharmacological blockade of synaptic transmission in parasympathetic pathways to the heart in rats

The blocking effects of newly synthesized compounds N-decyltropine bromide (IEM-1556) and its derivatives N-methyltropine iodide (IEM-1893) and N-hexyltropine iodide (IEM-1848), possessing aliphatic radicals of different length, on the vagus-induced reduction of the heart rate were studied in acute experiments on rats. The effects produced by these compounds on the level of arterial blood pressure and synaptic transmission in the superior cervical ganglion (SCG) of the rat were studied and compared with those produced by classical ganglion-blocking agents (hexamethonium and trimetaphan) and muscle relaxants (pancuronium and decamethonium). IEM-1556 much more effectively blocked the vagus-induced reduction of the heart rate than other tested blocking agents, and, in contrast to the classical ganglion-blocking agents and decamethonium, did not reduce the arterial blood pressure. In addition, IEM-1556 was less effective than hexamethonium in blocking synaptic transmission through the SCG. IEM-1893 and IEM-1848 demonstrated lower efficacy in blocking SCG transmission, if compared with that of IEM-1556. The results suggest that IEM-1556 is a highly selective blocking agent for parasympathetic versus sympathetic pathways, and its selectivity is determined by the presence of a decyl aliphatic radical in its molecule.Neirofiziologiya/Neurophysiology, Vol. 27, No. 5/6, pp. 323–330, September–December, 1995.     

Subunit Composition of Nicotinic Acetylcholine Receptors in Neurons of the Rat Intracardiac Ganglia

The effect of the antibodies against 3, 4, 5, and 7 subunits of neuronal nicotinic acetylcholine receptors (nAChR) on ACh-induced shifts of the membrane potential (ACh potentials) in neurons of the intracardiac ganglia of the rat left atrium was studied using intracellular electrodes. It was found that (i) antibodies against each of the above subunits caused only a partial block of ACh potential; (ii) the blocking effect of each particular antibody could be observed only in some of the examined neurons; (iii) in all neurons under study the block caused by a single antibody was only partial; (iv) the blocking effects of two or more antibodies on the ACh potential recorded from the same neuron were additive. It was concluded that (1) each of the above nAChR subunits is present only in a part of the intracardiac neurons, and (2) each intracardiac neuron has nAChR composed of more than one subunit.