Analysis of threshold currents during microstimulation of fibres in the spinal cord.

W. J. Roberts and D. O. Smith. Analysis of threshold currents during micro-stimulation of fibres in the spinal cord. Acta physiol. scand. 1973. 89. 384- 394. Fillies within the dorsal spinocerebellar tract of the cat were stimulated with current pulses from a mirroelertrode. With precise tracking, single nodes of Rainier of a fibre could be localized and the current required for activation studied as a function of the electrode position. The threshold stimulus amplitude was found to increase nonlinearly with distance from the node. The rate of increase in threshold was found to be less pronounced when the position of the electrode tip was changed axially rather than transversely to the node. The rates of increase with distance tended to decrease as the estimated fibre diameter became larger.

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