Local Potentials

Question 1

Depolarized

Answer 1

• A depolarized neuron cell membrane electrical potential is less negative than its resting membrane potential
• A depolarized neuron is more likely to generate an electrical signal
• A stimulus that results in depolarization is considered excitatory

Question 2

Hyperpolarized

Answer 2

• A hyperpolarized neurons cell membrane electrical potential is more negative than its resting membrane potential
• A hyperpolarized neuron is less likely to generate an electrical signal
• A stimulus that results in hyperpolization is considered inhibitory (difficult to transmit information)

Question 3

Local Potentials

Answer 3

• A small change in membrane potential for a short distance along the membrane following a stimulus
• Ion movement across the cell membrane creates a small decrease or increase in the negative charge

Question 4

If local potential is excitatory?

Answer 4

A small number of gated Na+ or Ca2+ channels open allowing some Na+ or CA2+ ions to flow down their concentration and electrical gradients into the cell (influx)

Question 5

If local potential is inhibitory?

Answer 5

A small number of gated channels open allowing either an influx of Chloride into the cell (most common) or an efflux of K+ out of the cell down their concentration gradients.