A model study of cellular short-term memory produced by slowly inactivating potassium conductances.
We analyzed the cellular short-term memory effects induced by a slowly inactivating potassium (Ks) conductance using a biophysical model of a neuron. We first described latency-to-first-spike and temporal changes in firing frequency as a function of parameters of the model, injected current and prior history of the neuron (deinactivation level) under current clamp. This provided a complete set of properties describing the Ks conductance in a neuron. We then showed that the action of the Ks conductance is not generally appropriate for controlling latency-to-first-spike under random synaptic stimulation. However, reliable latencies were found when neuronal population computation was used. Ks inactivation was found to control the rate of convergence to steady-state discharge behavior and to allow frequency to increase at variable rates in sets of synaptically connected neurons. These results suggest that inactivation of the Ks conductance can have a reliable influence on the behavior of neuronal populations under real physiological conditions.
Delord
B
B
INSERM U483, Université Pierre et Marie Curie, Paris, France.
Baraduc
P
P
Costalat
R
R
Burnod
Y
Y
Guigon
E
E
D000200:Action Potentials / Q000502:physiology; D002540:Cerebral Cortex / Q000166:cytology / Q000502:physiology; D008570:Memory, Short-Term / Q000502:physiology*; D008959:Models, Neurological; D009415:Nerve Net / Q000166:cytology / Q000502:physiology; D015221:Potassium Channels / Q000502:physiology*; D017966:Pyramidal Cells / Q000166:cytology / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013569:Synapses / Q000502:physiology / Q000648:ultrastructure; D013997:Time Factors
D015221:Potassium Channels