Lecture 3 - Brain cell communication & measurement techniques

What is the resting membrane potential of a neuron?

The resting membrane potential is approximately -70 mV, maintained by diffusion, electrostatic pressure, and the sodium-potassium pump.

How does the sodium-potassium pump maintain resting potential?

It pumps 3 Na+ ions out of the cell and 2 K+ ions into the cell against their concentration gradients, requiring ATP.

What triggers the opening of voltage-gated Na+ channels during an action potential?

The membrane potential reaching a threshold of -55 mV.

Define the "all-or-none law" of action potentials.

The strength of the action potential is independent of the stimulus intensity, and the action potential is always the same size.

What is saltatory conduction?

The jumping of action potentials from one node of Ranvier to the next in myelinated axons, which speeds up signal transmission.

Name three methods of terminating neurotransmitter action.

Diffusion, enzymatic degradation, and reuptake.

What is the main difference between ionotropic and metabotropic receptors?

Ionotropic receptors act faster and are involved in signaling, whereas metabotropic receptors act slower and are involved in modulation.

What are EEG and ERPs used for?

EEG measures electrical brain activity with high temporal resolution. ERPs detect brief changes in EEG signals in response to stimuli.

How does functional MRI (fMRI) measure brain activity?

It detects changes in blood oxygenation levels (BOLD signal) to infer neural activity.

What is a key advantage of MRI over CT scans?

It provides better resolution and structural details without using ionizing radiation.

What is transcranial magnetic stimulation (TMS) used for?

It non-invasively stimulates or inhibits brain regions and is used for research and treatment of conditions like depression.

Describe the relationship between neurotransmitter reuptake inhibitors and their effects.

Reuptake inhibitors, like SSRIs, block the reuptake of neurotransmitters, increasing their availability in the synapse.