Na+ Persistent Channels

Na+ Persistent Channels - B that exhibited...

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Main Purpose? The experiments performed in this paper are intended to better understand the Na + channels responsible for I NaP in EC stellate cells Why are these currents important? Many mammalian brain neurons exhibit a low-voltage-activated, slowly inactivating “persistent” Na + current (I NaP ) . These types of channels have been previously implicated in: Oscillatory activity Boosting of synaptic potentials Firing-pattern shaping Linked to the pathophysiology of epilepsy These currents contribute to oscillatory potentials. What’s the significance of this? The stellate cells of layer II (ECIIscs) play an important part in the genesis of the theta rhythm. These neurons occupy a key position in the neocortex- hippocampus-neocortex circuit, a crucial crossroad in memory functions. C : example of recordings obtained from the neuron shown in
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Unformatted text preview: B that exhibited "spontaneous " membrane potential oscillations on penetration by the microelectrode. - - -, membrane potential value ( 52 mV) during brief pauses of the oscillations. Note the characteristic AM of the oscillations. Oscillatory waves were composed of brief depolarizing and hyperpolarizing phases. TTX completely blocked the membrane potential oscillations, indicating that this activity depends on the activation of TTX-sensitive Na + current/s. In other neurons, TTX-sensitive membrane potential oscillations have been attributed to the activation of persistent Na + currents theta rhythm. These neurons occupy a key position in the neocortex-hippocampus-neocortex circuit, a crucial crossroad in memory functions...
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This note was uploaded on 04/07/2008 for the course NSCI 5461 taught by Professor Newman during the Spring '08 term at Minnesota.

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