Question

identify whether the following events would be classified as excitatory or inhibitory to a nueron.

potassium ions difussing outside a cell

hyperpolarization of the cell membrane within the trigger zone

sodium ions difussing into the cell

depolarization of the cell membrane within the trigger zone

Answer 1

1.potassium ions diffusing outside a cell will make the membrane potential more negative and will lead to hyperpolarization..It will be inhibitory to a neuron because it will increase the threshold stimulus for depolarization or action potential.

2.Hyperpolarization of the cell membrane within the trigger zone - it is the zone from where action potential is believed to be propagated along the axon.If membrane here gets hyper polarized,it will be inhibitory to a neuron.

3.Sodium ions diffusing into the cell will cause depolarization and therefore will generate action potential. Thus it is excitatory.

4.Depolarization of cell membrane within the trigger zone will have excitatory effect since it will propagate action potential along the axon.