[Diffusion modeling system of a neuron's molecular calculating machine].

Abstract

Intracellular injection of cyclic nucleotides through 3-4 barrel microelectrodes usually results in depolarization in case of cyclic AMP and in hyperpolarization in case of cyclic GMP. But sometimes the neuron response is more complex and changes with time. Phosphodiesterase inhibitors, papaverine, 3-isobutyl-1-methylxantine, SQ-20009 increase and prolong the effects of cyclic nucleotides and the complex effect of cyclic GMP is transformed into simple hyperpolarization. Large neurons respond to cyclic AMP with a delay (1-3 sec) after the beginning of iontophoresis. The solution of diffusion equation presents the distance from the microelectrode tip to the point of cyclic AMP action as a function of the delay (100-160 microns). The maximum value of concentration that may be reached at this point after a prolonged injection (10(-5) M) is calculated as well. The system producing and destroying cyclic nucleotides is supposed to be a diffusion analog input of the cell molecular computer. This system can solve various equations of mathematical physics. For this reason guanylatecyclase is supposed to be connected with special biochemical system which realizes harmonic analysis.