TY - JOUR

T1 - Detection of inhomogeneitis in membrain ohmic resistance in geometrycally complex systems

AU - Svirskis, G.

AU - Hounsgaard, J.

AU - Gutman, A.

PY - 2000/12/1

Y1 - 2000/12/1

N2 - DC field-evoked transients in arbitrary shaped neurons and syncytia were analyzed theoretically. In systems with homogeneous passive membrane properties the transients develop much faster than membrane discharges. The conduction of the proximal membrane could be larger due to the injury imposed by sharp electrode impalement. In this case, the transients have overshoot and undershoot when the field is switched on and off. The overshoot and undershoot decay with the time-constant of the response to the current injection. If conductance of the distal membrane is larger, then the fast transients develop only partially and have slow tails that decay according to the time-constant of the response to current injection. We recorded DC field-evoked potentials in motoneurons in turtle spinal cord slices by sharp electrodes and in the whole-cell mode. All three theoretically predicted types of responses were observed. We have found that sharp electrodes do not impose shunt in 60% of recorded cells. Detection of various membrane inhomogeneities in 1D-syncythium is discussed. We suppose also that it is possible to detect the inhomogeneities in intercellular resistance of the syncytium and intracellular resistance of a neuron when the membrane passive properties are homogeneous.

AB - DC field-evoked transients in arbitrary shaped neurons and syncytia were analyzed theoretically. In systems with homogeneous passive membrane properties the transients develop much faster than membrane discharges. The conduction of the proximal membrane could be larger due to the injury imposed by sharp electrode impalement. In this case, the transients have overshoot and undershoot when the field is switched on and off. The overshoot and undershoot decay with the time-constant of the response to the current injection. If conductance of the distal membrane is larger, then the fast transients develop only partially and have slow tails that decay according to the time-constant of the response to current injection. We recorded DC field-evoked potentials in motoneurons in turtle spinal cord slices by sharp electrodes and in the whole-cell mode. All three theoretically predicted types of responses were observed. We have found that sharp electrodes do not impose shunt in 60% of recorded cells. Detection of various membrane inhomogeneities in 1D-syncythium is discussed. We suppose also that it is possible to detect the inhomogeneities in intercellular resistance of the syncytium and intracellular resistance of a neuron when the membrane passive properties are homogeneous.

UR - http://www.scopus.com/inward/record.url?scp=0039763619&partnerID=8YFLogxK

M3 - Journal article

AN - SCOPUS:0039763619

VL - 17

SP - 324

EP - 329

JO - Biologicheskie Membrany

JF - Biologicheskie Membrany

SN - 0233-4755

IS - 3

ER -