Basic Neuroscience

Question 1

Action potential phases, ion channels, and components

Answer 1

• resting potential = -70 mV

- depolarizaition

Question 2

Concentration and direction of NA

Answer 2

• High concentration outside of cell

- flows into cell

Question 3

Concentration and direction of K

Answer 3

• high concentration inside of cell

- flows out of cell

Question 4

Concentration and direction of Ca

Answer 4

• high concentration outside of cell

- flows into cell

Question 5

Concentration and direction of Cl

Answer 5

• high concentration outside of cell

- flows into cell

Question 6

Do any of these ions travel against their electrical gradient? WHich ones?

Answer 6

K+ and Cl-

Question 7

Effect of Synaptic Potential is Determined by type of channel in post synaptic cell

Answer 7

• chloride channels allow chloride in to hyperpolarize the post synaptic membrane
• sodium channels allow sodium in to depolarize post synaptic membrane

Question 8

Refractory period

Answer 8

Can’t fire another action potential because sodium channels are out of the game (absolute refractory)
Little period of time before reactivation but before the baseline is reached when the cell is hyperpolarized (relative refractory)

Question 9

Ionotropic Receptors

Answer 9

Mechanisms of neurotransmitter receptor molecules.
After binding with a neurotransmitter, a directly coupled receptor undergoes a conformational (structural) change that opens the pore to permit ions to cross the membrane, leading to (in this case) depolarization of the postsynaptic neuron.

Question 10

Metabotropic Receptors

Answer 10

Mechanisms of neurotransmitter receptor molecules.
An indirectly coupled receptor binds the neurotransmitter but is not itself an ion channel and hence forms no pore. Instead, the binding of the neurotransmitter leads to a series of intracellular biochemical events, beginning with the action of G proteins and the subsequent generation of second messengers, ultimately leading to a signal that affects ion channels in the postsynaptic membrane, which then open and (in this case) depolarize the postsynaptic neuron.