Role of Architecture in Determining Passive Electrical Properties in Gap-Junction Connected Cells.

ANDREU, E., FERNANDEZ, E., LOUIS, E., ORTEGA G., SANCHEZ-ANDRES, J.

PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY

Año: 2000 vol. 439 p. 789 - 797

0031-6768

The electrical properties of gap junction-connectedcells were analysed in terms of their architecturalorganization. Two major architectural categories wereconsidered: trees and rings. Trees are described bymeans of Bethe lattices (lattices with no rings) with arbitraryco-ordination and rings by two-dimensional periodiclattices with fourfold (square) or sixfold (triangular)co-ordination. The Bethe lattice is solved analytically bythe transfer constant method, which allows the introductionof several physiologically relevant effects in a verysimple manner. The experimental data for the lengthconstant and the input resistance were fitted by varyingthe coupling and membrane resistances for various morphologies.The large variations in the length constant observedexperimentally in two systems (turtle retina horizontalcells with and without dopamine and pancreaticb-cells in the active and silent phases) could not be explainedby means of the Bethe lattice, indicating that thecell arrangements form rings. Subsequent analysis bymeans of a linear chain and the square and triangular latticesshowed the crucial relevance of architecture in derivingthe electrical characteristics of gap junctionconnectedcells from experimental data.