[The functional interrelation between Na/K-pump work, Na/Ca metabolism and the chemosensitivity of the neuronal membrane]. / Funktsional'naia vzaimosviaz' mezhdu rabotoi Na/K-nasosa, Na/Ca-obmenom i khemochuvstvitel'nost'iu neironal'noi membrany.

A correlation between the functions of Na/K-pump, Na/Ca-exchange and chemoreceptors in the membrane has been found. This correlation carries out through intracellular content of cyclic nucleotides. The low doses of transmitters which are unable to activate the chemosensitive ionic channels, have modulatory effect on the above mentioned membrane mechanisms.

[The cross desensitization and modulation of Cl currents activated by gamma-aminobutyric acid and L-glutamate in the isolated neurons of Aplysia]. / Perekrestnaia desensitizatsiia i moduliatsiia Cl-tokov, aktivirovannykh gamma-aminomaslianoi kislotoi i L-glutamatom, u odinochnykh neironov aplizii.

Chlorine conductance gated by gamma-aminobutyric acid (GABA) and L-glutamate in the medial pleural neurons of aplysia was studied using voltage clamp technique and a continuous microperfusion system that allowed rapid agonist application. Both GABA and glutamate elicited current responses that rapidly activated and then decayed. Glutamate response could be blocked by perfusion of aspartate or taurine and the GABA current showed voltage dependence. Thus the currents exhibited cross desensitization. It has been found that very low concentrations of acetylcholine (10(-8) to 10(-14) M) which have no electrophysiologic responses of their own, modulate the response to a constant application of GABA. During cooling the preparation blocked this effect, it is possible to suggest that the small doses of acetylcholine effect the membrane chemosensitivity through the cell biochemical mechanism.