Persistent Increases in Membrane Resistance of Neurons in Cat Motor Cortex.

摘要

The effect of various experimental procedures on membrane resistance was assessed in a total of 85 neurons in the coronal-pericruciate cortex of awake cats. Iontophoretic application of acetylcholine (ACh) extracellular to recorded cortical neurons was followed by transient increases in membrane resistance (Rm) in one-third of the encountered neurons. Pairing extracellular iontophoresis of ACh with concomitant intracellular current injection sufficient to repeatedly discharge the neuron led to persistent increases in cells that responded to ACh with an increase in RM. Rm was not increased if saline was substituted for ACh or if the neuron was only discharged repeatedly. Pairing extracellular iontophoresis of ACh with current injection just insufficient to repeatedly discharge the neuron prolonged the transient increase in Rm to ACh, but Rm eventually returned to base-line levels.