Chapter 2 - Synapses

Question 1

Neurons communicate at specialized junctions called ____.

Answer 1

Synapses

Question 2

In the late 1800’s, ____ _ ____ anatomically demonstrated a narrow gap separating one neuron from another.

Answer 2

Ramon y Cajal

Question 3

In 1906, _____ ___ _____ physiologically demonstrated that communication between one neuron and the next differs from communicating along a single axon (not an AP).

Answer 3

Charles Scott Sherrington

Question 4

___ and ___ are considered the great pioneers of modern neuroscience.

Answer 4

Cajal, Sherrington

Question 5

Sherrington had used ____ properties to infer the major properties of the synapse half a century before researchers had the technology to measure those properties directly.

Answer 5

Behavioural

Question 6

1. Sherrington studied ____, automatic muscular responses to stimuli.
2. In a leg flexion reflex, a sensory neuron excites a ___ neuron, which in turn excites a ____ neuron.
3. The circuit from a sensory neuron to a motor neuron is called a ____ arc.
4. When Sherrington pinched a dog’s leg, the leg ___, and the pother legs ___.
5. After a dog’s spinal cord was severed from his brain, the same reflexive movement ___.
6. The spinal cord therefore controls the ___ and ___ reflexes.

Answer 6

1. Reflexes
2. Second, motor
3. reflex
4. Flexed, extended
5. Remained
6. Flexion and extension.

Question 7

In an intact animal (brain and spinal cord connected), messages descending from the brain ____ the reflexes, making them stronger at some times and weaker at others.

Answer 7

Modify

Question 8

In conclusion: Sherrington observed several properties of reflexes that suggest special processes at the junctions between neurons:

1) Reflexes are slower than conduction along an ___.
2) Several weak stimuli presented at nearby places or times produce a stronger reflex than ___ stimulus alone dories.
3) When one set of muscles becomes excited, a different set becomes ____.

Answer 8

1) axon
2) one
3) relaxed, inhibited

Question 9

Previous research had concluded that APs have a speed of about __m/s, while the speed of a reflex arc was about __m/s

Answer 9

40m/s, 15m/s

Question 10

Sherrington found that repeated stimuli within a brief time had a cumulative effect. he referred to this phenomenon as as ____ ____.

Answer 10

Temporal Summation

Question 11

Elliot (1905)

Adrenaline applied to surface of heart,stomach, and pupils mimics ___ ___ ___.

Answer 11

Sympathetic nervous system

Question 12

Calcium enters the Neuron body, triggering the release of NT, this is called ____

Answer 12

Exocytosis (exp = out, cytosine = transport) 1-2 ms

Question 13

Difference between a Ionotropic and Metabotropic effects (difference between Hormone and NT)

Answer 13

Ionotropic = NT, quick, quickly open potassium (+) ion channels, uses the NT glutamate (the most abundant NT) - depolarizes membrane 
Metabotropic = hormone, slow acting, released in to region, open chloride gates (-) channels. Hyperpolarizes membrane. Uses NT GABA

Question 14

Glycine is an ____ NT and is found mostly in the Spinal cord.

Answer 14

Inhibitory

Question 15

Acetylcholine is an ____ NT, and is found at Ionotropic synapses

Answer 15

Excitatory

Question 16

ACTIVATION AND REUPTAKE

1) After acetylcholine activates a receptor, the enzyme acetylcholine_____ breaks it into two fragments: ___ and ___.
2) The choline diffuses back in the ____ neuron, which takes it and reconnects with ____ to form ______.
3) It does not reabsorb all the ____ it releases, and it takes time, thus a sufficiently rapid series of action potentials ____ the NT, faster than the presynaptic cell replenishes it, thus slowing or interrupting ___.

Answer 16

1) acetylcholonesterase, acetate and choline
2) presynaptic, acetate, acetylcholine
3) molecules, deplete, transmission

Question 17

1. Serotonin and catecholamines ( ___, ___, and ___), do not break down into active fragments at the postsynaptic membrane. They simply ____ from the receptor.
2. At that point, the next steps varies, the presynaptic neuron takes up much or most of the released intact and ____ them.
3. This process is called ___
4. This process is done through special membranes called ____.

Answer 17

1. Norepinephrine, epinephrin, dopamine. Detach
2. Reuses
3. Reuptake
4. Transporters

Question 18

Amino Acids which contain an ___ group.

1) G___
2) g__

Answer 18

Amine

1) GABA
2) Glutamate

Question 19

1) Long chains of amino acids:____
Including poly____ and proteins
2) En____, ____ P, ____ Y

Answer 19

1) Peptides, peptides

2) Endorphins, Substance, substance

Question 20

1. Acetylcholine: similar to ____ acids, but structurally different
2. Comprised of ____ coenzyme A and ____.
3. When broken down forms into ____ and ___.
4. Enzyme called acetylchole_____ breaks down acetylcholine

Answer 20

1. Amino
2. Acetyl, choline
3. Acetate and choline
4. Acetylcholinesterase

Question 21

1. Nonacidic neurotransmitter containing an amine group (“bioamines”): ____
2. These have a catechol ring and two Hydroxl [OH] groups attached the them.
3. They also form what 3 NT?
4. This has a complex double organic ring called an indoor ring.
5. It is an ____

Answer 21

1. Monoamines
2. Catecholamines
3. Epinephrine, Norepinephrine, and Dopamine
4. Serotonin
5. Indolamine

Question 22

ATP, Adenosine and it’s derivatives are called these NTs

Answer 22

Purines.

Question 23

This is the only known gas to act as a NT

what does it do?

Answer 23

Nitric oxide [NO]

Dilate blood vessels

Question 24

Action potential causes what to enter which releases NT?

Answer 24

Calcium

Question 25

Neurons synthesize NT from substances in the ___

Answer 25

Diet

Question 26

Peptide NT synthesized from ___ ___ provided by diet | Acetylcholine is synthesized from ___ which is abundant in ___ and milk

Answer 26

Amino acids | Choline, cauliflower

Question 27

This precursor to serotonin is important in the brain and increases after a meal rich in protein

Answer 27

Tryptophan

Question 28

Small NT are synthesized in ____ terminals, close to release point

Answer 28

Terminals

Question 29

Larger NY, like peptides, are synthesized in the ___ body and transported slowly down the axon. They are not reabsorbed and ____ like many smaller NT, thus they are exhausted ___

Answer 29

cell | Recycled, quickly

Question 30

The release of NT through the membrane is called:

Answer 30

Exocytosis

Question 31

Usually 2 or 3 transmitters are released from each neuron; always the same ____ Dale’s Law: a mature neuron makes use of the same NT at all of its synapses. This was proved ___ Daly’s law was proved false, and many mature neurons contain more than one NT, this is referred to as ____, and usually contains a low-molecular weight NT and a ____ peptide

Answer 31

Combination False Coexistence, neuroactive

Question 32

Dale’s Law has been reformulated to: a neuron makes use of the same _____ of chemical messengers at all of its synapses, but neurons may receive and respond to many more.

Answer 32

Combination

Question 33

Activations at receptors Ionotropic 1. Quick start (___ms) and a short duration (__ms) 2. Localized effect on ____ 3. Immediately opens gates for ions; eg ____ 4. Most abundant: ____ (excitatory) 5. Most abundant inhibitory: ___ 6. Ionotropic synapses for ____ events like visual stimulation, muscle movements etc.

Answer 33

1. 10, 30 2. Membrane 3. Acetylcholine 4. Glutamate 5. GABA 6. Quick

Question 34

Metabotropic effects 1. Late start (__ms) 2. Activates _-protein 3. G-protein ___/___ ion channels, changes protein ______, or activates ____ in cell

Answer 34

1. 30ms 2. G 3 opens/closes, production, chromosomes

Question 35

These NTs are mainly peptides, they are chemicals released in small quantities that diffuse to nearby cells, and act at metabolic receptors; and are long lasting. Chemicals released in larger quantities in blood stream and act like Metabotropic NT Epinephrine, Norepinephrine, Insulin, oxytocin and others act as both ____, and ____

Answer 35

Neuromodulators Hormones NTs and hormones

Question 36

These act as NT and hormones (INOE)

Answer 36

Insulin, Norepinephrine, oxytocin, epinephrine,

Question 37

1. A drug that mimics or increases the effect of a NT | 2. A drug that blocks or takes away the effects of the NT

Answer 37

1. Agonist | 2. Antagonist

Question 38

Ability of a drug to bind to a receptor. (How long it says on the receptor) The degree to which the drug activates the receptor once bound

Answer 38

Affinity | Efficacy

Question 39

D_ receptor related to alcohol consumption, rec. drugs use, overeating and habitual gambling D_ related to being impulsive, exploratory and quick-tempered, schizophrenia, no link to personality

Answer 39

D2 receptor | D4 receptor

Question 40

Acetylcholine has at least _ types of nicotine and _ types of muscarinic receptors Dopamine has _ typos of receptors Seratonin has __ types of receptors

Answer 40

4, 5 5 15