A subscription to JoVE is required to view this content.  Sign in or start your free trial.
Measurement of Evoked Potassium Ion Concentration Dynamics in Coronal Hippocampal Slices

Measurement of Evoked Potassium Ion Concentration Dynamics in Coronal Hippocampal Slices

Transcript

Secure a mouse coronal brain slice in a recording chamber filled with aCSF.

Insert a bipolar stimulating electrode into the stratum radiatum of the CA3 region in the hippocampus. The CA3 neurons project their axons, termed Schaffer collaterals, to CA1.

Position a potassium ion-selective electrode in the CA1 stratum radiatum.

Electrically stimulate CA3 neurons to open voltage-gated sodium channels. The sodium ion influx turns the membrane potential positive, termed depolarization, and generates an action potential.

After the peak of depolarization, sodium channels deactivate, and voltage-gated potassium channels allow potassium ion outflow, repolarizing the membrane. Subsequently, the membrane potential is restored, and the action potential propagates to CA1.

The potassium ion-selective electrode measures the outflow, shown by a response curve.

Add a blocker to inhibit voltage-gated sodium channel activity. Upon electrical stimulation, a lack of potassium ion response confirms that its dynamics are due to action potentials in the Schaffer collaterals.

Related Videos

Read Article