Neuroscience 1 (Winter 2023)

What is responsible for the fluctuations in the resting membrane potential of a neuron before an action potential?

• voltage-gated sodium channels

• the influence of nearby neurons

• voltage-gated potassium channels

• sodium-potassium pumps

Scientists have discovered a rare condition that causes people to have no chloride channels on their neurons. Which of the following would be true regarding the functioning of the neurons in these people?

• Temporal and spatial summation will not occur.

• More stimulation will be required to cause the membrane potential to reach the threshold.

• Neurons will fire action potentials more often than normal.

• Synapses will cause the membrane potential of the presynaptic neuron to increase.

which of the following is correct regarding the process of neurogenesis?

• the neural plate curves upwards and begins to form the inside of the neural tube by day 21

• the inside of the neural tube forms the inner brain, while the outside of the neural tube forms the cortex

• founder cells are on the outside of the neural tube forming the spinal cord

• during the entire process of neurogenesis, cell division is symmetrical; each founder cell produces one founder cell and one neuron or glial cell

A neuron at resting potential receives simultaneous stimulation from several different presynaptic neurons. Presynaptic neuron 1 provides an EPSP of 5mV, presynaptic neuron 2 provides an EPSP of 10mV, and presynaptic neuron 3 provides an IPSP of 6mV. Will the neuron fire an action potential?

• Due to spatial summation, the neuron will reach threshold and therefore will fire an action potential.

• Due to spatial summation, the neuron will not reach threshold and therefore will not fire an action potential.

• Due to temporal summation, the neuron will not reach threshold and therefore will not fire an action potential.

• Due to temporal summation, the neuron will reach threshold and therefore will fire an action potential.

which of the following is true of synaptic transmission?

• a dendrite from the presynaptic neuron transmits its signal to the terminal end of the postsynaptic neuron

• an IPSP occurs when the cell depolarizes, making it less likely to fire an action potential

• one EPSP causes the neuron to reach threshold and fire an action potential

• neurotransmitter binding causes ions to enter the postsynaptic neuron