Communication in the Brain Flashcards
How do signals move from one end of a neuron to another?
Processing electrical signals
What did Luigi Galvani discovered?
Discovered that animals can move due to electricity. He realized that a frog’s leg twitched when touched by a metal probe.
What did Volta add to Galvani’s theory?
Correctly proposed that the frog’s leg twitched because of the small electrical current that the metal probe had.
What was the conclusion made after Galvani’s and Volta’s discoveries?
It was found out that muscles could be stimulated directly, but the effect was even stronger if the muscle nerve was stimulated.
What is electricity?
electrically-charged particles move from one place to another.
What is electrical potential? What is its unit?
The tendency to move. It measured in volts.
What is the resting potential of a neuron?
- 70 mv
When a neuron is in resting potential, it is…
polarized
What happens when the sodium channels open and a bunch of positively charged ions (cations) rush in?
The neuron becomes depolarized.
What is an ion?
A molecule or ion with a net electrical charge, depending on the gain or loss of one or more electrons.
How do neurons send signals?
Action potential
Why is depolarization a positive feedback loop?
When one area becomes depolarized, this causes a chain reaction and causes other areas to also become depolarized.
What happens when a neuron reaches -50mv?
An action potential will happen, no matter what.
How long does an action potential last?
One millisecond
What is the speed of an action potential?
30 to 120m/s
How is information passed from one neuron to another?
Through the synapse, which is part of chemical communication
What is the synapse?
Contact point between two neurons.
What is the synapse also known by?
Inter-neuron information transfer
What is the synapse made up of?
Synaptic cleft, post-synaptic neuron and pre-synaptic neuron.
Example of an inhibitory neurotransmitter
GABA
Example of an excitatory neurotransmitter
Glutamate
What do excitatory post-synaptic potentials do?
increases the chances of an actional potential happening again.
What do inhibitory post-synaptic potentials do?
Decreases the chances of an action potential happening again.
What is temporal summation?
How close together the EPSPs are in time or space determines whether action potential will occur or not.
What are the major classes of neurotransmitters?
Aminoacids, peptides, monoamines and others
What neurotransmitters fall under “aminoacids”?
y-aminobutyric acid (GABA), glutamate, and glycine
What neurotransmitters fall under “monoamines”?
norepinephrine (NE), epinephrine (EP), serotonin (5-HT), and dopamine (DA)
What neurotransmitters fall under “peptides”?
oxytocin, vasopressin and neuropeptide Y
What neurotransmitters fall under “others”?
Acetylcholine (Ach), adenosine, anandamide, nitric oxide
What would happen if neurotransmitters remained in the synaptic cleft?
They would keep stimulating the post-synaptic neuron
What are the 4 major ways used to deactivate neurotransmitters?
Diffusion, degradation, reuptake and glial cells
What is diffusion?
Some of the neurotransmitters float away from the synaptic cleft, which prevents from continuing to stimulate the post-synaptic neuron.
What is reuptake?
Specialized proteins, known as reuptake transporters, take neurotransmitters back into the pre-synaptic neuron to recycle them.
What is degradation?
Specialized enzymes break neurotransmitters down into inactive molecules.
