Synaptic Transmission

Question 1

Is Synaptic Transmission Chemical or Electrical?

Answer 1

Chemical

Question 2

Lowei’s Critical Experiment

Answer 2

Frog Hearts and Vagas Nerves in a Solution He discovered the first neurotransmitter and named it Vagustoffe (now known as acetylcholine.

Question 3

What was the first neurotransmitter?

Answer 3

Acetylcholine

Question 4

Who discovered the first neurotransmitter?

Answer 4

Loewi

Question 5

Where are Neurotransmitters synthesized?

Answer 5

in the presynaptic neuron

Question 6

Where are thee molecules of neurotransmitters stored?

Answer 6

Synaptic vesicles in the cytoplasm of the presynaptic terminal

Question 7

What is the role of synaptic vesicles?

Answer 7

Store neurotransmitter molecules until they are ready to be released.

Question 8

What causes neurotransmitters to be released into the synaptic cleft?

Answer 8

Action potential caused by the influx of calcium ions.

Question 9

Describe exocytosis

Answer 9

Calcium ion channels open causing an influx in calcium. The membranes of the vesicle and the cell fuse together allowing the neurotransmitters to diffuse out on their own. This is done through passive diffusion.

Question 10

What does the neurotransmitter do once it is in the synaptic cleft?

Answer 10

Binds to a chemically gated protein receptor on the postsynaptic membrane.

Question 11

What’s the difference between ionotropic and metabotropic?

Answer 11

Ionotropic are fast acting, short lived.

Metabotropic are slow acting, lasts longer and are more durable and persistent.

Question 12

What are metabotropic receptors?

Answer 12

bind to a protein but they do not open a channel. An enzyme is activated and makes substance A into Substance B. Eventually a substance will be madee and bind to protein and open ion channel. It is much slower because it has to go through a cascade of metabolic changes called the second messenger system.

Question 13

Excitatory postsynaptic potential (EPSP)

Answer 13

Depolarization usually through an influx of sodium or calcium ions.

Question 14

Which ions cause an Excitatory Postsynaptic Potential?

Answer 14

Sodium and Calcium

Question 15

What Ion is necessary for exocytosis?

Answer 15

Calcium

Question 16

What happens when depolarization occurs?

Answer 16

Excitatory Postsynaptic Potential occurs

Question 17

Inhibitory Postsynaptic Potential (IPSP)

Answer 17

Hyperpolarization through thee influx of chloride or potassium

Question 18

What ions cause Inhibitory Postsynaptic Potential to occur?

Answer 18

Chloride and Potassium

Question 19

What happens when hyperpolarization occurs?

Answer 19

Inhibitory Postsynaptic Potential

Question 20

During hyperpolarization _______ leaves the cell leaving the inside more negative.

Answer 20

Potassium

Question 21

During hyperpolarization ______ enters the cell causing the inside to be more negative.

Answer 21

Chloride

Question 22

What are the three fates of a neurotransmitter?

Answer 22

Degradation by catabolic enzymes in the synapse
Re-uptake and degradation in cytoplasm of presynaptic terminal
Re-uptake and redepositing back into a synaptic vesicle.

Question 23

Which neurotransmitters fall subject to all three fates? And which fate is most common for these neurotransmitters?

Answer 23

Dopamine and Norepinephrine

Re-uptake and redeposit