Afterhyperpolarization Conductance Research Articles

Afterhyperpolarization conductance time course in lumbar motoneurones of the cat.

AbstractThe time and potential dependence of the conductance process (es) underlying the longlasting afterhyperpolarization (AHP) in the cat's a‐motoneurones were studied. The conductance changes were determined by injection of short current pulses. The conductance time course was characterized by a longlasting exponential decay interrupted by a plateau corresponding to the slower hypcrpolarizing phase of the AHP. By displacing the membrane potential in the subthreshold region with the injection of longlasting current pulses it was found that the conductance was largely unaffected by membrane potential displacements. Similar characteristics were found when calculating the AHP conductance time course from the AHP voltage. It was concluded that the AHP in motoneurones is given by a potassium conductance process with this complex S‐shaped time course. A mathematical expression describing this time course is given.

Computer simulation of rhythmic oscillations in neuron pools

This paper describes computer simulation of 100 artificial neurons interconnected in mutually exciting random pools. The individual neuromimes include accommodation according to an extended version of Hill's model and adaptation according to an extended version of Kernell's model. The main finding is that the constituent cells of the pools tend to fire in coordinated bursts and that these bursts recur rhythmically. The rate of burst recurrence depends primarily on the time constant of recovery of the after-hyperpolarization conductance change although it may be slightly altered by the average level of random background activity. It does not seem possible to attribute the salient slow rhythm observed in the rat mesencephalic reticular formation to this mechanism, as matching the data requires absurdly large values of the conductance change recovery time constant.

Repetitive discharge rate of a simple neuron model with accumulation of after-hyperpolarization conductance.

Repetitive discharge rate of a simple neuron model with accumulation of after-hyperpolarization conductance.

Regulation of repetitive firing in motoneurones by the afterhyperpolarization conductance

Regulation of repetitive firing in motoneurones by the afterhyperpolarization conductance